Multidimensional Analyses of the Learning Curve of Endoscopic Thyroidectomy.

BACKGROUND: Endoscopic thyroidectomy has comparable surgical outcomes and superior cosmetic satisfaction to open thyroidectomy. However, steep learning curve is a concern. This study evaluated the learning curve of endoscopic thyroidectomy using various parameters and statistical methods. METHODS: A total of 90 consecutive patients who underwent endoscopic thyroidectomy using bilateral axillo-breast approach (BABA) between March 2016 and April 2020 were enrolled. Operative time, postoperative drainage amount, and blood loss were assessed by cumulative sum (CUSUM) analysis and moving average to evaluate the learning curve. RESULTS: Using the CUSUM analysis, the peak point of both operative time and drainage amount occurred at the 30th case. No clear single peak was identified in the CUSUM plot for blood loss. The moving average also showed significant reduction in operative time and drainage amount after, approximately, the first 30 cases. The blood loss decreased after the 25th case. We therefore divided the patients into 2 phases: phase 1 (1-30 cases) and phase 2 (31-90 cases). The operative time, drainage amount, and blood loss decreased significantly in the phase 2 compared with phase 1. Lower pain score in first postoperative day and shorter hospital stay were also observed in the phase 2. Although the reduction in transient hypoparathyroidism did not reach statistical significance, no permanent hypoparathyroidism was noted in the phase 2. CONCLUSIONS: The learning curve for endoscopic thyroidectomy is approximately 30 cases. Aside from the operative time, drainage amount may also serve as a surrogate for the learning curve evaluation.

Outcome Comparison between Endoscopic Transoral and Bilateral Axillo-Breast Approach Thyroidectomy Performed by a Single Surgeon.

BACKGROUND: The transoral approach and the bilateral axillo-breast approach (BABA) are remote access approaches for endoscopic thyroidectomy. Both follow a symmetric design and use CO2 insufflation to maintain the working space. The outcome differences between the techniques are rarely compared in the literature. METHODS: All patients who underwent endoscopic transoral (n = 72) and BABA (n = 63) thyroidectomy between October 2018 and August 2020 by a single surgeon were retrospectively reviewed. The following peri-operative data were collected and compared: operative time, blood loss, postoperative drainage amount, hospital stay, pain score, number of retrieved lymph nodes, and complications. RESULTS: Patients in the transoral group were younger (44.7 vs. 49.3 years, p = 0.022) and had smaller tumors (2.4 vs. 2.8 cm, p = 0.020) than those in the BABA group. The operative times were significantly longer in the transoral group than in the BABA group (lobectomy, 194.1 vs. 177.0 min, p = 0.026; total thyroidectomy, 246.0 vs. 214.3 min, p = 0.042). Nevertheless, the time difference became insignificant after completing the initial 20 cases of transoral thyroidectomy. The drainage fluid collected after the surgery was serosanguinous, and a lower drainage volume was observed in the transoral group than that in the BABA group (64.9 vs. 78.5 ml, p = 0.017). However, there was no significant difference regarding the blood loss, hospital stay, postoperative pain score, and lymph nodes retrieved. The rate of postoperative complications, such as hypoparathyroidism and vocal cord palsy was comparable between the two groups. CONCLUSIONS: Transoral approach and BABA are comparable with regard to surgical outcomes. Selected patients may choose either technique based on their preferences.

Foley Balloon Facilitates Creation of Working Space in Transoral Thyroidectomy.

BACKGROUND: Transoral thyroidectomy via the vestibular approach retains no scars in the body surface and is a good option for patients indicated for thyroidectomy but with cosmetic concerns. However, the working space of this procedure is relatively small and is also difficult to create compared with that of other remote-access thyroidectomy procedures. METHODS: In this study, we first created a tract from the chin to the sternal notch, after which a Foley catheter with stylet was inserted through the middle oral incision. Sequential balloon insufflations were performed to dilate the entire subplatysmal tunnel. RESULTS: After Foley catheter dilatation, the subplatysmal space was larger, and subsequent trocar insertion became much easier. With the help of a balloon compressing the surrounding tissue, hemostasis was secured and a clearer tissue plane could be identified for subsequent sharp dissection. CONCLUSIONS: Foley balloon dilatation is a simple, effective, and low-cost technique that overcomes the difficulty in creation of working space during the initial stage and can be applied to all transoral thyroidectomy procedures.

One-Pot Tandem Photoredox and Cross-Coupling Catalysis with a Single Palladium Carbodicarbene Complex.

The combination of conventional transition-metal-catalyzed coupling (2 e- process) and photoredox catalysis (1 e- process) has emerged as a powerful approach to catalyze difficult cross-coupling reactions under mild reaction conditions. Reported is a palladium carbodicarbene (CDC) complex that mediates both a Suzuki-Miyaura coupling and photoredox catalysis for C-N bond formation upon visible-light irradiation. These two catalytic pathways can be combined to promote both conventional transition-metal-catalyzed coupling and photoredox catalysis to mediate C-H arylation under ambient conditions with a single catalyst in an efficient one-pot process.

Refractive collimation beam shaper design and sensitivity analysis using a free-form profile construction method.

A refractive laser beam shaper comprising two free-form profiles is presented. The profiles are designed using a free-form profile construction method such that each incident ray is directed in a certain user-specified direction or to a particular point on the target surface so as to achieve the required illumination distribution of the output beam. The validity of the proposed design method is demonstrated by means of ZEMAX simulations. The method is mathematically straightforward and easily implemented in computer code. It thus provides a convenient tool for the design and sensitivity analysis of laser beam shapers and similar optical components.

Paraxial ray-tracing equations for optical systems containing triangular prisms.

Conventional paraxial ray-tracing procedures are widely used for optical systems design and analysis. However, they are not applicable to multiple-dispersion-prism systems. Accordingly, the present study simplifies the equations given by the present group in a previous paper [Optik117, 329 (2006)OTIKAJ0030-402610.1016/j.ijleo.2005.10.004] to the form of 3×3 matrix equations for tracing paraxial rays in optical systems containing triangular prisms. The accuracy and validity of the proposed approach are demonstrated by means of four numerical examples. The results confirm that the proposed equations provide a convenient and practical tool for analyzing paraxial rays traveling through non-axially symmetrical optical systems containing triangular and rectangular prisms.

Free-form surface design method for a collimator TIR lens.

A free-form (FF) surface design method is proposed for a general axial-symmetrical collimator system consisting of a light source and a total internal reflection lens with two coupled FF boundary surfaces. The profiles of the boundary surfaces are designed using a FF surface construction method such that each incident ray is directed (refracted and reflected) in such a way as to form a specified image pattern on the target plane. The light ray paths within the system are analyzed using an exact analytical model and a skew-ray tracing approach. In addition, the validity of the proposed FF design method is demonstrated by means of ZEMAX simulations. It is shown that the illumination distribution formed on the target plane is in good agreement with that specified by the user. The proposed surface construction method is mathematically straightforward and easily implemented in computer code. As such, it provides a useful tool for the design and analysis of general axial-symmetrical optical systems.

Design and analysis of reflector for uniform light-emitting diode illuminance.

A light-emitting diode (LED) projection system is proposed, composed of an LED chip and a variable-focus-parabolic (VFP) reflector, in which the focal length varies as a function of the vertical displacement of the incidence point relative to the horizontal centerline of the LED chip. The light-ray paths within the projection system are analyzed using an exact analytical model and a skew-ray tracing approach. The profile of the proposed VFP reflector and the position of the LED chip are then optimized in such a way as to enhance the uniformity of the illuminance distribution on the target region of the image plane. The validity of the optimized design is demonstrated by means of ZEMAX simulations. It is shown that the optimized VFP projector system yields a significant improvement in illuminance uniformity compared to conventional spherical and parabolic projectors and therefore minimizes the glare effect.

Design of optically stable image reflector system.

The design of a partially optically stable (POS) reflector system, in which the exit ray direction and image pose are unchanged as the reflector system rotates about a specific directional vector, was presented in an earlier study by the current group [Appl. Phys. B100, 883-890 (2010)]. The present study further proposes an optically stable image (OSI) reflector system, in which not only is the optical stability property of the POS system retained, but the image position and total ray path length are also fixed. An analytical method is proposed for the design of OSI reflector systems comprising multiple reflectors. The validity of the proposed approach is demonstrated by means of two illustrative examples.

HOXC8 mediates osteopontin expression in gastric cancer cells.

Genes of the homeobox (HOX) family encode transcription factors, which play a role in cancer progression. However, their role in gastric cancer has not been adequately evaluated. Herein, we evaluated the genetic changes and mRNA of target genes of the HOX family in gastric cancer patients using publicly available online datasets. We found that HOXC8 was amplified in gastric cancer tissues, and mRNA expression levels were significantly associated with tumor status (P=0.044) and poor overall survival (P<0.01). HOXC8 knockdown significantly reduced the viability of gastric cancer cell lines. HOXC8 modulated the expression of secreted phosphoprotein 1 (SPP1, osteopontin) and phosphorylation of AKT/ERK in gastric cancer cells. Survival analysis demonstrated a decrease in overall survival rates among the high HOXC8/high SPP1 expression group compared with the low HOXC8/low SPP1 expression group. In conclusion, HOXC8 may be an independent prognostic factor and serve as a useful predictive biomarker for gastric cancer.

Laparoscopic versus open subtotal gastrectomy for locally advanced gastric cancer: A retrospective analysis from a single institution.

BACKGROUND: /Objective: Laparoscopic distal gastrectomy for early gastric cancer is described as a treatment option in general practice. However, the oncological efficacy and technical safety of laparoscopic gastrectomy with D2 lymphadenectomy in locally advanced gastric cancer are controversial, and clinical trials are ongoing. This study aimed to evaluate the short-term and surgical outcomes between laparoscopic and open gastrectomy procedures in locally advanced gastric cancer. METHODS: We retrospectively analyzed data from 134 patients who underwent subtotal D2 gastrectomy for locally advanced gastric cancer in our hospital between January 2011 and December 2018. Clinicopathological characteristics, surgical outcome, postoperative recovery, disease-free survival, and overall survival were compared between those who underwent laparoscopic and open gastrectomies. RESULTS: Baseline characteristics were similar between patients who underwent open and laparoscopic surgeries. Less surgical time (250.8 vs. 347.6 min in laparoscopic vs. open surgery, respectively; P < 0.05) and lower blood loss (83.7 vs. 333 mL in laparoscopic vs. open surgery, respectively; P < 0.05) were noted in patients who underwent laparoscopic surgery than in those who underwent open gastrectomy. The time of starting oral intake was earlier and the length of postoperative hospital stay was shorter in the laparoscopic group than in the open group. Surgical morbidity and mortality rates, as well as disease-free survival and overall survival rates, did not differ between the two groups. CONCLUSION: Laparoscopic gastrectomy is feasible and safe for locally advanced gastric cancer. Based on the perioperative results and short-term outcomes, laparoscopic gastrectomy is non-inferior to open gastrectomy.

Exact analytical approach for six-degree-of-freedom measurement using image-orientation-change method.

An exact analytical approach is proposed for measuring the six-degree-of-freedom (6-DOF) motion of an object using the image-orientation-change (IOC) method. The proposed measurement system comprises two reflector systems, where each system consists of two reflectors and one position sensing detector (PSD). The IOCs of the object in the two reflector systems are described using merit functions determined from the respective PSD readings before and after motion occurs, respectively. The three rotation variables are then determined analytically from the eigenvectors of the corresponding merit functions. After determining the three rotation variables, the order of the translation equations is downgraded to a linear form. Consequently, the solution for the three translation variables can also be analytically determined. As a result, the motion transformation matrix describing the 6-DOF motion of the object is fully determined. The validity of the proposed approach is demonstrated by means of an illustrative example.

Determination of unit normal vectors of aspherical surfaces given unit directional vectors of incoming and outgoing rays.

Snell's law describes the relationship between the incidence angle and reflection (or refraction) angle of a light ray impinging on the interface between two different isotropic media. In this paper, Snell's law is used to derive the unit normal vectors of an aspherical surface given a knowledge of the unit directional vectors of the incoming and outgoing rays. The proposed method has important applications in the design and fabrication of aspherical surfaces since the surface normal vectors determine not only the optical performance of the surface but also the cutting tool angles required to machine the surfaces.

Determination of first-order derivatives of skew ray at aspherical surface.

A set of algorithms is proposed for determining the first-order derivatives of a skew ray with respect to all the independent variables of an aspherical boundary surface in a general 3D optical system. Ellipsoidal, paraboloidal, hyperboloidal, and cylindrical boundary surfaces are given as examples. The proposed method has important applications in the analysis of aspherical surfaces and enables a detailed understanding of a wide variety of optical effects, including reflection and refraction, the modulation transfer function, and aberrations.

X-shaped Breast Lift to Improve Surgical Ergonomics in Bilateral Axillo-Breast Approach Thyroidectomy.

BACKGROUND: Endoscopic thyroidectomy through the bilateral axillo-breast approach (BABA) is a good option for patients who have been advised thyroid resection but are concerned about the cosmetic results. This technique uses the breast tissue as a pivot to facilitate maneuvering of the surgical instruments. However, it is difficult to use this technique in patients with small breasts or having a flat chest. MATERIALS AND METHODS: The authors developed an "X-shaped breast lift" method using fabric adhesive tape, to push up and augment the breast tissue to facilitate the thyroid dissection procedure. Changes before and after the breast lift were quantified by measuring the angle of breast tilt and the distance between relevant anatomic landmarks. RESULTS: Fifteen consecutive patients underwent this procedure before undergoing BABA thyroidectomy. The mean breast tilt angle increased from 3.2 to 9.8 degrees, which is a >3-fold increase (+6.6 degree, 206%). The mean distance between the cricoid cartilage and nipple was reduced by 1.9 cm (-8%), and the mean distance between the axillary incision and nipple increased by 1.1 cm (9%). No skin trauma or ulceration was observed. CONCLUSIONS: X-shaped breast lift is easy to perform, and it significantly improves the thyroid dissection process with no significant adverse effects. It can be used for all cases of BABA thyroidectomy.

Single Biaxillary Tunneling for Working Space Creation in Bilateral Axillo-Breast Approach (BABA) Thyroidectomy.

BACKGROUND: Endoscopic thyroidectomy using the bilateral axillo-breast approach (BABA) achieves excellent cosmetic results. However, concerns have been raised about the extensive dissection and violation of the breast during working space preparation. MATERIALS AND METHODS: We developed a "single biaxillary tunneling" technique for working space creation in BABA thyroidectomy; this technique was applied in 30 cases. RESULTS: Skin bruise was hardly visible, and only minor and small bruises were observed. The whole process of working space creation typically finished within 20 to 30 minutes. CONCLUSIONS: Limited blunt dissection by a single stroke of biaxillary tunneling is a simple method, which significantly reduces ecchymosis formation and is time-efficient. This method can be used in routine practice and is feasible for beginner surgeons.

Incarcerated Hiatal Hernia with Perforation after Laparoscopic Total Gastrectomy with Roux-en-Y Reconstruction: a Case Report.

The occurrence of hiatal hernia after total gastrectomy with Roux-en-Y reconstruction is rare. We report the case of a 76-year-old man who presented with dyspnea, vomiting, and fever around 8 days after total gastrectomy with Roux-en-Y reconstruction. Abdominal computed tomography revealed a hiatal hernia containing part of the small intestine in the left thoracic cavity. Emergent reduction and repair of the hiatal hernia were performed later. Operative findings revealed that the Roux limb was incarcerated in the left pleural cavity. Esophagojejunostomy leakage, perforation of the small intestine with transient ischemic change, and pyothorax were also found. Thus, feeding jejunostomy, thoracoscopic decortication, and diversion T-tube esophagostomy were performed. Considering that the main cause of hiatal hernia is blunt dissection with division of the phrenoesophageal membrane, approximating the crus with 1 or 2 figure-8 sutures, according to the size of the defect, to prevent the incidence of hiatal hernia after total gastrectomy may be performed.

Aberrant DNA Hypermethylation Silenced LncRNA Expression in Gastric Cancer.

BACKGROUND/AIM: Long noncoding RNAs (lncRNAs) are noncoding transcripts that are >200 nucleotides in length. However, the biological functions and regulation mechanisms of lncRNAs in gastric carcinogenesis remain unknown. MATERIALS AND METHODS: The expression levels of Linc00472 were analyzed by real-time PCR. The DNA methylation status was assessed using Combined Bisulfite Restriction Analysis (COBRA). The biological role of Linc00472 was assessed in AGS cells with Linc00472 overexpression. RESULTS: Using the next-generation sequencing approach, we identified DNA methylation-associated lncRNAs in gastric cancer cells. Among them, the expression level of Linc00472 significantly decreased in gastric cancer tissues compared to adjacent normal tissues. Furthermore, we observed a more frequent hypermethylation of CpG islands upstream of Linc00472 in gastric cancer tissues. Ectopic Linc00472 expression could significantly inhibit gastric cancer cell growth and migration. CONCLUSION: Epigenetically regulated Linc00472 expression plays a crucial role in modulating gastric cancer cell growth and motility.

MiR-193a-5p and -3p Play a Distinct Role in Gastric Cancer: miR-193a-3p Suppresses Gastric Cancer Cell Growth by Targeting ETS1 and CCND1.

BACKGROUND/AIM: MicroRNAs (miRNAs) are small non-protein-coding RNAs, that can be generated from the 5p or 3p arm of precursor miRNA (pre-miRNA). Differential miRNA arm selection has been reported between tumor and normal tissue in many cancer types; however, the biological function and mechanism of miRNA arm switching in gastric cancer remain unclear. MATERIALS AND METHODS: Profiles of miRNA expression in gastric cancer were obtained from The Cancer Genome Atlas (TCGA). The biological role of miR-193a-5p/-3p in tumor growth and invasive abilities was assessed through a gain-of-function approach. Target genes of miR-193a-3p were identified using bioinformatics and an experimental approach. RESULTS: The expression levels of miR-193a-5p, and not of miR-193a-3p, were significantly decreased in gastric cancer compared to adjacent normal tissues. Ectopic expressions of miR-193a-5p and miR-193a-3p revealed that they both inhibited gastric cancer cell growth, but only miR-193a-3p significantly suppressed cell invasion ability. Using a bioinformatics approach, we identified 18 putative target genes of miR-193a-3p. Both mRNA and protein levels of cyclin D1 (CCND1) and ETS proto-oncogene 1 (ETS1) were significantly decreased in AGS cells transfected with miR-193a-3p mimics. ETS1 or CCND1 knockdown significantly suppressed gastric cancer cell growth, similar to miR-193a-3p overexpression. CONCLUSION: Our results indicated that miR-193a-3p suppressed gastric growth and motility, at least partly, by directly targeting CCND1 and ETS1 expression.