• Clinics in Shoulder and Elbow
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• v.24 no.3
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• pp.135-140
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• 2021

Background: We hypothesized in this study that the characteristics of retear cases vary according to surgeon volume and that surgical outcomes differ between primary and revision arthroscopic rotator cuff repair (revisional ARCR). Methods: Surgeons performing more than 12 rotator cuff repairs (RCRs) per year were defined as high-volume surgeons, and those performing fewer than 12 RCRs were considered low-volume surgeons. Of the 47 patients who underwent revisional ARCR at our clinic enrolled in this study, 21 cases were treated by high-volume surgeons and 26 cases by low-volume surgeons. In all cases, the interval between primary surgery and revisional ARCR, degree of "acromial scuffing," number of anchors, RCR technique, retear pattern, fatty infiltration, retear size, operating time, and clinical outcome were recorded. Results: During primary surgery, significantly more lateral anchors (p=0.004) were used, and the rate of use of the double-row repair technique was significantly higher (p<0.001) in the high- versus low-volume surgeon group. Moreover, the "cut-through pattern" was observed significantly more frequently among the cases treated by high- versus low-volume surgeons (p=0.008). The clinical outcomes after revisional ARCR were not different between the two groups. Conclusions: Double-row repair during primary surgery and the cut-through pattern during revisional ARCR were more frequent in the high- versus low-volume surgeon groups. However, no differences in retear site or size, fatty infiltration grade, or outcomes were observed between the groups.

• Journal of International Society for Simulation Surgery
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• v.2 no.1
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• pp.26-32
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• 2015

Purpose When a surgeon examines the morphology of skull of patient, locations of craniometric landmarks of 3D computed tomography(CT) volume are one of the most important information for surgical purpose. The locations of craniometric landmarks can be found manually by surgeon from the 3D rendered volume or 2D sagittal, axial, and coronal slices which are taken by CT. Since there are many landmarks on the skull, finding these manually is time-consuming, exhaustive, and occasionally inexact. These inefficiencies raise a demand for a automatic localization technique for craniometric landmark points. So in this paper, we propose a novel method through which we can automatically find these landmark points, which are useful for surgical purpose. Materials and Methods At first, we align the experimental data (CT volumes) using Frankfurt Horizontal Plane (FHP) and Mid Sagittal Plane(MSP) which are defined by 3 and 2 cranial landmark points each. The target landmark of our experiment is the anterior nasal spine. Prior to constructing a statistical cubic model which would be used for detecting the location of the landmark from a given CT volume, reference points for the anterior nasal spine were manually chosen by a surgeon from several CT volume sets. The statistical cubic model is constructed by calculating weighted intensity means of these CT sets around the reference points. By finding the location where similarity function (squared difference function) has the minimal value with this model, the location of the landmark can be found from any given CT volume. Results In this paper, we used 5 CT volumes to construct the statistical cubic model. The 20 CT volumes including the volumes, which were used to construct the model, were used for testing. The range of age of subjects is up to 2 years (24 months) old. The found points of each data are almost close to the reference point which were manually chosen by surgeon. Also it has been seen that the similarity function always has the global minimum at the detection point. Conclusion Through the experiment, we have seen the proposed method shows the outstanding performance in searching the landmark point. This algorithm would make surgeons efficiently work with morphological informations of skull. We also expect the potential of our algorithm for searching the anatomic landmarks not only cranial landmarks.

• Journal of Veterinary Clinics
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• v.40 no.6
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• pp.438-444
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• 2023

The aim of this study was to analyze the learning curve of a low-volume veterinary surgeon for laparoscopic salpingectomy of Asiatic black bear. A total of 66 Asiatic black bears (Ursus thibetanus) were presented for sterilization using laparoscopic salpingectomy. These 66 bears were divided into three groups of 22 bears according to the order of surgery (A, B, and C groups, 22 bears per group). One veterinarian performed laparoscopic salpingectomy. There was no significant difference in age, body weight, or crown-rump length between groups. The hazard of completion for salpingectomy by 5 minutes was higher (p < 0.0001) in B and C groups than A group, whereas the hazard was not significant different between B and C groups. The factor that affected the hazard of completing salpingectomy by 5 minutes was heart rate, not age or weight. Operation time was 12.61 ± 8.04 minutes for group A, 5.35 ± 4.38 minutes for group B, and 2.80 ± 1.16 minutes for group C. The operation time for salpingectomy shortened over time. However, significant difference in operation time was present only between groups A and C (p = 0.001). The operation time for laparoscopic salpingectomy decreased rapidly for the first 7 bears (p < 0.05). It then decreased gradually until the 66th case. Operation time of laparoscopic salpingectomy was significantly decreased and stabilized after 33 cases (p < 0.05). As a result, the number of bears required for a low-volume veterinary surgeon to be proficient in laparoscopic salpingectomy is 33 or more.

• Journal of International Society for Simulation Surgery
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• v.2 no.1
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• pp.33-39
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• 2015

Purpose The head of infants under 24 months old who has Craniosynostosis grows extraordinarily that makes head shape unusual. To diagnose the Craniosynostosis, surgeon has to inspect computed tomography(CT) images of the patient in person. It's very time consuming process. Moreover, without a surgeon, it's difficult to diagnose the Craniosynostosis. Therefore, we developed technique which detects Craniosynostosis automatically from the CT volume. Materials and Methods At first, rotation correction is performed to the 3D CT volume for detection of the Craniosynostosis. Then, cranial area is extracted using the iterative thresholding method we proposed. Lastly, we diagnose Craniosynostosis by analyzing centroid relationships of clusters of cranial bone which was divided by cranial suture. Results Using this automatical cranial detection technique, we can diagnose Craniosynostosis correctly. The proposed method resulted in 100% sensitivity and 90% specificity. The method perfectly diagnosed abnormal patients. Conclusion By plugging-in the software on CT machine, it will be able to warn the possibility of Craniosynostosis. It is expected that early treatment of Craniosynostosis would be possible with our proposed algorithm.

• Archives of Plastic Surgery
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• v.48 no.6
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• pp.607-613
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• 2021

Background Breast reconstruction using an extended latissimus dorsi (eLD) flap can supplement more volume than reconstruction using various local flaps after partial mastectomy, and it is a valuable surgical method since the reconstruction area is not limited. However, when performing reconstruction, the surgeon should consider latissimus dorsi (LD) volume reduction due to postoperative chemotherapy (POCTx) and postoperative radiotherapy (PORTx). To evaluate the effect of POCTx and PORTx on LD volume reduction, the effects of each therapy-both separately and jointly-need to be demonstrated. The present study quantified LD volume reduction in patients who underwent POCTx and PORTx after receiving breast-conserving surgery (BCS) with an eLD flap. Methods This study included 48 patients who received immediate breast reconstruction using an eLD flap from January 2013 to March 2017, had chest computed tomography (CT) 7-10 days after surgery and 10-14 months after radiotherapy completion, and were observed for more than 3 years postoperatively. One surgeon performed the breast reconstruction procedures, and measurements of breast volume were obtained from axial CT views, using a picture archiving and communication system. A P-value <0.05 was the threshold for statistical significance. Results The average volume reduction of LD at 10-14 months after completing POCTx and PORTx was 64.5% (range, 42.8%-81.4%) in comparison to the volume measured 7-10 days after surgery. This change was statistically significant (P<0.05). Conclusions Based on the findings of this study, when harvesting an eLD flap, surgeons should anticipate an average LD volume reduction of 64.5% if chemotherapy and radiotherapy are scheduled after BCS with an eLD flap.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.2.1-2.6
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• 2019

Objectives: This study was aimed to analyze the reducing pattern of decompression on mandibular odontogenic keratocyst and to determine the proper time for secondary enucleation. Materials and methods: Seventeen patients with OKC of the mandible were treated by decompression. Forty-five series of CT data were taken during decompression and measured by using InVivo software (Anatomage, San Jose, Calif) and were analyzed. Results: The expected relative volume during decompression is calculated using the following formula: V(t) = V_initial × exp.(at + 1/2bt²) (t = duration after decompression (day)). There was no significant directional indicator in the rate of reduction between buccolingual and mesiodistal widths. Conclusion: The volume reduction rate gradually decreased, and 270 days were required for 50% volume reduction following decompression of OKC. The surgeon should be aware of this pattern to determine the timing for definitive enucleation. Clinical relevance: The volume reduction rate and pattern of decompression of the OKC can be predicted and clinicians should be considered when treating OKC via decompression.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.203-208
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• 2013

Background Preoperative volume assessment is useful in breast reconstruction. Magnetic resonance imaging (MRI) and mammography are commonly available to reconstructive surgeons in the care of a patient with breast cancer. This study aimed to verify the accuracy of breast volume measured by MRI, and to identify any factor affecting the relationship between measured breast volume and actual breast weight to derive a new model for accurate breast volume estimation. Methods From January 2012 to January 2013, a retrospective review was performed on a total of 101 breasts from 99 patients who had undergone total mastectomy. The mastectomy specimen weight was obtained for each breast. Mammographic and MRI data were used to estimate the volume and density. A standard statistical analysis was performed. Results The mean mastectomy specimen weight was 340.8 g (range, 95 to 795 g). The mean MRI-estimated volume was $322.2mL^3$. When divided into three groups by the "difference percentage value", the underestimated group showed a significantly higher fibroglandular volume, higher percent density, and included significantly more Breast Imaging, Reporting and Data System mammographic density grade 4 breasts than the other groups. We derived a new model considering both fibroglandular tissue volume and fat tissue volume for accurate breast volume estimation. Conclusions MRI-based breast volume assessment showed a significant correlation with actual breast weight; however, in the case of dense breasts, the reconstructive surgeon should note that the mastectomy specimen weight tends to overestimate the volume. We suggested a new model for accurate breast volume assessment considering fibroglandular and fat tissue volume.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.631-635
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• 2012

Background The evaluation of a breast after breast reconstruction depends on a surgeon's subjective criteria. We used computed tomography (CT) scans to obtain an objective evaluation of the postoperative results by measuring the breast volume of patients who had undergone breast reconstruction using pedicled transverse rectus abdominis myocutaneous (TRAM) flaps. This research will help in the objective postoperative evaluation of reconstructed breasts, and also in the preoperative flap size designs. Methods A total of 27 patients underwent breast reconstruction using pedicled TRAM flaps after mastectomy from September 2007 to July 2010. Of these, 10 patients who were followed up and underwent CT scans 2 or more times during the follow-up period were included in this study. We evaluated the change in breast volume over time using CT scans, and the interval breast volume change between CT scans. Results All of the 10 patients' reconstructed breasts showed a volume decrease over time. The breast volume changes in the intervals between CT scans were as follows: 5.65% decrease between the first CT and second CT scan, 2.3% decrease between the second CT and third CT scan, (statistically significant) and 1.89% decrease between the third CT and forth CT scan. (not statistically significant). Conclusions This research shows the possibility of objectively evaluating the postoperative breast volume changes. The findings will be helpful in designing the size of TRAM flaps to use on defects after mastectomy. Based on these results, we should also closely observe the reconstructed breast volume for at least 2 years.

• Archives of Plastic Surgery
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• v.44 no.5
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• pp.413-419
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• 2017

Background In breast reconstruction using implants after unilateral mastectomy, it is challenging to create a natural, ptotic contour, and asymmetry is a potential drawback. To achieve breast symmetry and an ideal shape for both breasts, we performed contralateral augmentation in patients undergoing breast reconstruction with implants. Methods Patients underwent unilateral mastectomy and 2-stage reconstruction. During the second stage of the procedure, contralateral augmentation mammoplasty was performed. Preoperatively, we obtained the patients' demographic information, and we then assessed breast volume, the volume and dimensions of the inserted implants, and complications. Breast symmetry was observed by the surgeon and was assessed by measuring the disparity between the final volume of each breast. Results Contralateral augmentation was performed in 52 cases. When compared to patients who did not undergo a contralateral balancing procedure, patients who received contralateral augmentation were younger, thinner, and had smaller breasts. During implant selection for contralateral augmentation, we chose implants that were approximately 1 cm shorter in width, 1 level lower in height, and 1 or 2 levels lower in projection than the implants used for reconstruction. The postoperative breast contours were symmetric and the final volume discrepancy between each breast, which was measured by 3-dimensional scanning, was acceptable. Conclusions We demonstrate that contralateral augmentation can be recommended for patients who perceive their breasts to be small and not beautiful in order to achieve an ideal and beautiful shape for both breasts. Furthermore, this study offers guidelines for selecting the implant that will lead to the optimal aesthetic outcome.

• Journal of the Korean Society of Radiology
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• v.16 no.1
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• pp.53-59
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• 2022

DEXA, as the standard areal bone mineral density (aBMD) measurement method, often shows an insuficient correlation between aBMDs of the measured bones and referring bones and is inaccurate due to the mass effect. In contrast, quantitative computer tomography (QCT), as a volumetric BMD (vBMD) measurement method, is being advanced so that it uses less radiation before, owing to improved CT device and computer imaging technology. Because dual-energy CTs can modulate the image signals showing tumor or specific chemicals as well as the ability to measure vBMD, they are expanding their application. For pre-checking vBMD of surgeon-specific bone volume at implantation candidate sites, a finite element creation-based local vBMD measurement technique was developed. The local vBMD measurement function for surgeon-specific shape volumes will be added to clinical imaging systems.