• Journal of Minimally Invasive Surgery
• /
• v.21 no.4
• /
• pp.160-167
• /
• 2018

Purpose: The aim of our study was to present an abdominal wall closure technique using barbed suture $V-Loc^{TM}$ 90 after single incision laparoscopic appendectomy (SILA) and to compare perioperative outcomes with conventional layer by layer abdominal wall closure after SILA. Methods: From March 2014 to July 2016, a retrospective case-control study was conducted for a total of 269 consecutive patients who underwent SILA. According to abdominal wall closure methods, 129 patients were classified into the V-Loc closure group and 140 patients were assigned into the conventional layer by layer closure group. In the V-Loc group, abdominal wall closure was performed from the fascia to the skin with a single thread of unidirectional absorbable barbed suture $V-Loc^{TM}$ 90 2-0 using continuous running suture and reverse overlapping reinforced running technique. Subcutaneous closure and subcuticular suture were performed with the remaining portion of V-Loc. Results: The V-Loc closure group showed shorter total operation time ($40.0{\pm}15.4min$ vs. $44.9{\pm}16.3min$, p=0.013) and abdominal wall cusing continuous running suture and reverse overlapping reinforced running technique. Subcutaneous closure and subcuticular suture were performed with the remaining portion of V-Loc. Results: The V-Loc closure group showed shorter total operation time losure time ($5.5{\pm}0.9min$ vs. $6.5{\pm}0.8min$, p<0.001). Postoperative incision length was significantly shorter in the V-Loc closure group ($1.1{\pm}0.3cm$ vs. $1.8{\pm}0.4cm$, p<0.001). Postoperative wound pain, time to resume diet, postoperative hospital stay, complications including surgical site infection, or mean patient satisfaction score at one month after hospital discharge was not significantly different between the two groups. Conclusion: In conclusion, unidirectional knotless barbed suture is a safe alternative method for abdominal wall closure after SILA. It can save time while providing comparable cosmesis.

• The Journal of Korea Robotics Society
• /
• v.7 no.2
• /
• pp.120-128
• /
• 2012

The loop closure problem is one of the most challenging issues in the vision-based simultaneous localization and mapping community. It requires the robot to recognize a previously visited place from current camera measurements. While the loop closure often relies on visual bag-of-words based on point features in the previous works, however, in this paper we propose a line-based method to solve the loop closure in the corridor environments. We used both the floor line and the anchored vanishing point as the loop closing feature, and a two-step loop closure algorithm was devised to detect a known place and perform the global pose correction. We propose an anchored vanishing point as a novel loop closure feature, as it includes position information and represents the vanishing points in bi-direction. In our system, the accumulated heading error is reduced using an observation of a previously registered anchored vanishing points firstly, and the observation of known floor lines allows for further pose correction. Experimental results show that our method is very efficient in a structured indoor environment as a suitable loop closure solution.

• Transactions of Materials Processing
• /
• v.16 no.2 s.92
• /
• pp.126-131
• /
• 2007

Voids in a large rotor are formed in solidification process of a cast ingot. The voids have to be eliminated from the rotor by a forming process, because they would became stress-intensity factors which suddenly fracture the rotor in the operation. Previous studies on void-elimination of a large rotor have mainly focused on finding the process variables affecting the void-closure. But the study on the amount of void closure in a large rotor has been very rare. This study was performed to obtain an equation which predicts the amount of void-closure in a forging process of a large rotor and to evaluate the availability of the void-closure equation through finite element analyses. Firstly, 2D FE analysis was carried out to find effects of time integral of hydrostatic stress and effective strain on void volume rate of a large rotor in the upsetting process for various diameters and shapes of void, and material temperature. From the 2D FE analysis, we found that effective strain was suitable for predicting the void-closure of a large rotor, because there was a constant relationship between void volume rate and effective strain. And a void-closure equation was proposed fur predicting void-closure of a large rotor in the upsetting process. Finally, ken the 3D FE analysis, the proposed void-closure equation was verified to be useful for upsetting and cogging processes.

• Journal of Korean Neurosurgical Society
• /
• v.51 no.1
• /
• pp.31-36
• /
• 2012

Objective : The purpose of this study was to elucidate the anatomical development of physiologic suture closure processes in infants using three dimensional reconstructed computed tomography (CT). Methods : A consecutive series of 243 infants under 12 months of age who underwent three dimensional CT were included in this study. Four major cranial sutures (sagittal, coronal, lambdoidal and metopic suture) were classified into four suture closure grades (grade 0=no closure along the whole length, grade 1=partial or intermittent closure, grade 2=complete closure with visible suture line, grade 3=complete fusion (ossification) without visible suture line), and measured for its closure degree (suture closure rates; defined as percentage of the length of closed suture line divided by the total length of suture line). Results : Suture closure grade under 12 months of age comprised of grade 0 (n=195, 80.2%), grade 1 (n=24, 9.9%) and grade 2 (n=24, 9.9%) in sagittal sutures, whereas in metopic sutures they were grade 0 (n=61, 25.1%), grade 1 (n=167, 68.7%), grade 2 (n=6, 24%) and grade 3 (n=9, 3.7%). Mean suture closure rates under 12 months of age was 58.8% in metopic sutures, followed by coronal (right : 43.8%, left : 41.1%), lambdoidal (right : 27.2%, left : 25.6%) and sagittal sutures (15.6%), respectively. Conclusion : These quantitative descriptions of cranial suture closure may help understand the process involved in the cranial development of Korean infants.

• Clinical and Experimental Pediatrics
• /
• v.53 no.12
• /
• pp.1012-1017
• /
• 2010

Purpose: Transcatheter closure has become an effective therapy in most patients with patent ductus arteriosus (PDA). However, there are difficulties in transcatheter closure of PDA in small children. We reviewed clinical outcomes of transcatheter closure of PDA in children weighing less than 10 kg in a single center. Methods: Between January 2003 and December 2009, 314 patients with PDA underwent transcatheter closure in our institute. Among them, 115 weighed less than 10 kg. All of these patients underwent transcatheter closure of PDA using either COOK Detachable $Coil^{(R)}$, PFM Nit-$Occlud^{(R)}$, or Amplatzer duct $occluder^{(R)}$. A retrospective review of the treatment results and complications was performed. Results: The mean age of patients was $9.1{\pm}5.9$ months (median, 8 months), and mean weight was $7.6{\pm}1.8kg$ (median, 7.8 kg). The mean diameter of PDA was $3.2{\pm}1.4mm$ (median, 3 mm). Complete occlusion occurred in 113 patients (98%). One patient was sent to surgery because of a failed attempt at device closure, and another patient had a small residual shunt after device placement. The average mean length of hospital stay was $3.0{\pm}3.3$ days, and mean follow-up duration was $21.0{\pm}19.6$ months. There were no major complications in any of the patients. Conclusion: Transcatheter closure of PDA is considered safe and efficacious in infants weighing less than 10 kg. With sufficient experience and further effort, transcatheter closure of PDA can be accepted as the gold standard of treatment for this group of patients.

• The Korean journal of sports medicine
• /
• v.36 no.4
• /
• pp.180-188
• /
• 2018

Purpose: The purpose of this study is to identify bilateral differences of physeal closure of the lateral compartment of the elbow in osteochondritis dissecans (OCD) and related factors with premature physeal closure. Methods: Initial radiographs of the bilateral elbows in 40 baseball players with OCD (group I) were reviewed for the status of physeal closure of the lateral compartment; capitellum, radial head, lateral epicondyle. Forty baseball players with medial epicondylar apophysitis (group II) were enrolled as a control. Relative status of physeal closure of dominant elbow was defined as early, same, and delayed. Bilateral differences of the status of physeal closure were analyzed between groups, and according to the radiographic stages, extent of the lesions and demographic factors in group I. Results: Significant early physeal closures of dominant elbows were identified in group I in capitellum (group I, 55%; group II, 3%), radial head (group I, 53%; group II, 3%), and lateral epicondyle (group I 37%; group II, 5%). In group I, advanced stage and extended lesion showed early lateral compartment physeal closure especially in capitellum and radial head, and players with longer career length and limitation of motion showed early closure. Conclusion: Over the half of the adolescent baseball players with OCD demonstrated early radiocapitellar physeal closures of dominant elbow in initial presentation. Because premature physeal closure contributes to the development of arthritis without appropriate radiocapitellar remodeling, early detection of OCD is essential for prevention of arthritis and successful conservative management.

• Journal of Chest Surgery
• /
• v.34 no.6
• /
• pp.485-489
• /
• 2001

Background: The most important factor in preventing sternal complications is stable sternal approximation. We have tried to find the most effective sternal closure method by examining the incidence of sternal dehiscence with or without infection in patients with cardiac surgery through median sternotomy. Material and Method: This study was performed in 489 patients over 45 years of age with median sternotomy for open cardiac surgery. Simple closure with interrupted 6 wires was performed in 159 patients, figure-of-8 closure technique in 119, overlapping interrupted closure using 10 wires in 150, and combined closure technique of interrupted simple closure and figure-of-8 suture closure in 61. Two hundred thirty-four patients underwent valve and aortic operations and 213 patients coronary artery bypass surgery. Result: Sternal dehiscence with or without infection occurred in 12 (2.5 %) patients. The complication developed in 5 of 159 patients (3.1%) with six interrupted simple closure, in 4 of 119 patients (3.4%) with figure-of-8 closure, and in 3 of 150 patients (2.0%) with overlapping interrupted closure using 10 wires, but there was no complication in 61 patients with combined closure technique (relative risk for other closure techniques, p<0.05). There was no significant difference in the incidence of the sternal complication between valve and aortic operation group and coronary artery bypass group (3.0% vs 2.3%, not significant), but diabetes mellitus was a significant independent risk factor (odds ratio and multivariate analysis, p<0.05). Conclusion: The sternal closure technique that combines simple interrupted suture closure and figure-of-8 suture closure may be a more useful technique to enhance sternal stabilization compared to other closure techniques, such as simple interrupted closure, 8-figure closure, and overlapping interrupted closure.

• Journal of Chest Surgery
• /
• v.28 no.4
• /
• pp.335-339
• /
• 1995

Secundum atrial septal defect occupies about 10 to 15% of congenital heart diseases, and the surgical accomplishment is outstanding, so that the operative mortality is getting near to zero percent. But, the methods of correction, direct closure versus patch closure are still controversial and there is no absolute method about it. Some surgeons prefer direct closure technique for its simplicity and lesser thrombogenicity but others, afraid of arrhythmia and suture detachment after closure of large defect, prefer patch closure. Usually most surgeons use direct suture technique in small and moderate sized defects and patch closure in large defects. In our hospital, 156 cases of isolated secundum atrial septal defect were closed directly by double continuous over and over suture using 5-0 polypropylene[prolene , regardless their sizes and the amounts of shunt flow. There were no operative mortality and no serious complications such as heart block, suture detachment and embolism.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.8
• /
• pp.1181-1185
• /
• 2006

By using two different computer simulation methods, of which one produces exact results while the other is based on the Wilemski-Fixman closure approximation, we evaluate the utility of closure approximation in calculating the rates of diffusion-controlled reactions involving a reactant with multiple reaction sites. We find that errors in the estimates of steady-state rate constants due to closure approximation are not so large. We thus propose an approximate analytic expression for the rate constant based on the closure approximation.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.5
• /
• pp.797-804
• /
• 2001

To obtain representative fatigue crack growth characteristic curve in residual stress field, fatigue crack growth test was carried out at various stress ratio and fatigue crack growth characteristic curve was represented using crack closure concept. Obtained results are as follows;K(sub)op/K(sub)max was independent of K(sub)max when R was lower than 0.5 and crack closure phenomenon was not observed when R is higher than 0.5. therefore neglecting crack closure behaviour, actual fatigue crack growth rate can be underestimated. Thus, considering crack closure phenomenon, fatigue crack growth characteristics curve of A 106 Gr B Steel weldment can be effectively estimated.