1.Minimally invasive techniques for lateral maxillary sinus floor elevation: small lateral window and one-stage surgery-a 2-5-year retrospective study.
Shaojingya GAO ; Yao JIANG ; Yangxue YAO ; Songhang LI ; Xiaoxiao CAI
International Journal of Oral Science 2023;15(1):28-28
		                        		
		                        			
		                        			This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach (lSFE) and to determine the factors that influence the stability of the grafted area in the sinus cavity. Thirty patients (30 implants) treated with lSFE using minimally invasive techniques from 2015 to 2019 were included in the study. Five aspects of the implant (central, mesial, distal, buccal, and palatal bone heights [BHs]) were measured using cone-beam computed tomography (CBCT) before implant surgery, immediately after surgery (T0), 6 months after surgery (T1), and at the last follow-up visit (T2). Patients' characteristics were collected. A small bone window (height, (4.40 ± 0.74) mm; length, (6.26 ± 1.03) mm) was prepared. No implant failed during the follow-up period (3.67 ± 1.75) years. Three of the 30 implants exhibited perforations. Changes in BH of the five aspects of implants showed strong correlations with each other and BH decreased dramatically before second-stage surgery. Residual bone height (RBH) did not significantly influence BH changes, whereas smoking status and type of bone graft materials were the potentially influential factors. During the approximate three-year observation period, lSFE with a minimally invasive technique demonstrated high implant survival rate and limited bone reduction in grafted area. In conclusion, lSFE using minimally invasive techniques was a viable treatment option. Patients who were nonsmokers and whose sinus cavity was filled with deproteinized bovine bone mineral (DBBM) had significantly limited bone resorption in grafted area.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Maxillary Sinus/surgery*
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Sinus Floor Augmentation
		                        			;
		                        		
		                        			Bone Resorption
		                        			;
		                        		
		                        			Cone-Beam Computed Tomography
		                        			
		                        		
		                        	
2.Feasibility study of immediate breast reconstruction with fusion fascia combined with implants.
Zu Jin CHEN ; Ao Xiang CHEN ; Bin ZHANG ; Xin WANG ; Xu Chen CAO
Chinese Journal of Oncology 2023;45(6):514-518
		                        		
		                        			
		                        			Objective: To investigate the oncologic and surgical safety of the fused fascia method for immediate breast reconstruction with implants. Methods: The clinical data of 343 patients with immediate breast reconstruction with implants in Tianjin Medical University Cancer Hospital from 2014-2017 were retrospectively analyzed to compare the 5-year local recurrence-free survival, 5-year disease-free survival and 5-year overall survival of patients with breast reconstruction by fusion fascia and other methods, and to analyze the complication incidences of implant removal between different implant groups. Results: Of the 343 patients with breast reconstruction, 95 were in the fused fascia group (fascia group) and 248 were in the non-fascia group (25 in the bovine pericardial patch group and 223 in the muscle flap group). At a median follow-up of 49 months, the differences in 5-year local recurrence-free survival (90.1% and 94.9%, respectively), 5-year disease-free survival (89.2% and 87.6%, respectively), and 5-year overall survival (95.2% and 95.1%, respectively) between patients in the fascial and non-fascial groups were not statistically significant (P>0.05). The complication incidence of implant removal was 24.0% (6/25) in the patch group and 2.1% (2/95) and 2.2% (5/223) in the fascia and muscle flap groups, respectively. Conclusion: Immediate breast reconstruction with fused fascial combined with implant is safe and feasible, less invasive than muscle flaps, more economical and with fewer complications than patches.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Mastectomy/methods*
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Breast Implants/adverse effects*
		                        			;
		                        		
		                        			Feasibility Studies
		                        			;
		                        		
		                        			Mammaplasty/methods*
		                        			;
		                        		
		                        			Breast Neoplasms/complications*
		                        			;
		                        		
		                        			Treatment Outcome
		                        			;
		                        		
		                        			Postoperative Complications/surgery*
		                        			
		                        		
		                        	
3.Application of acellular bovine pericardium patch in implant based immediate breast reconstruction.
Bo Wen DING ; Hui Qing WANG ; Shan Shan HE ; Shu WANG ; Qing Feng HUANG ; Chun Yong HAN ; Jing LIU ; Zhu Ming YIN ; Jing Yan SUN ; Yan WANG ; Jian YIN
Chinese Journal of Surgery 2022;60(3):237-243
		                        		
		                        			
		                        			Objective: To examine the clinical effect of acellular bovine pericardium patch in implant based immediate breast reconstruction. Methods: The clinicopathological information of 141 breast cancer patients, who admitted to Department of Breast Reconstruction and Oncoplastic Surgery, Tianjin Medical University Cancer Hospital, underwent immediate mammoplasty with implants combined with acellular bovine pericardium patches were analyzed from June 2016 to October 2019. All patients were female, with the age of (38.8±8.5) years (range: 13 to 60 years). The body mass index was (21.9±2.5) kg/m2 (range: 16.0 to 32.3 kg/m2). There were 39 cases of duct carcinoma in situ, 46 cases of stage Ⅰ, 40 cases of stage Ⅱ and 16 cases of stage Ⅲ. All patients received nipple-areola-sparing mastectomy or skin-sparing mastectomy with sentinel lymph node biopsy or axillary lymph node dissection, and prosthesis implantation with sub-pectoralis combined with breast patch. The correlation of clinicopathological characters and complications was assessed by t test, χ2 test, Fisher's exact probability method and Logistic regression. Pre-and post-operative aesthetic, quality of life scores were recorded. Results: The operation time (M(IQR)) was 3.6(1.5) hours (range: 3.0 to 6.5 hours). The early postoperative complication rate was 22.0% (31/141), prosthesis removal was the main postoperative complication, accounting for 64.5% (20/31) of the total complications, of which 15 cases occurred in the first 30 patients. The follow-up time was 28(8) months (range: 20 to 53 months), The most frequent long-term complications were capsular contracture and implant displacement, with the incidence of 11.2% (14/125) and 10.4% (13/125), respectively. Multivariate analysis showed that prosthesis volume ≥300 ml (OR=8.173, 95%CI: 1.302 to 51.315, P=0.021) and peri-areolar incision (OR=7.809, 95%CI: 2.162 to 28.211, P<0.01) were independent relative factors for the occurrence of short-term postoperative local complications. After 2 years of operation, the score of breast appearance satisfaction was 71.7±15.5, postoperative effect satisfaction was 90.4±9.5, psychological satisfaction was 90.7±17.1, sexual satisfaction was 70.1±25.1. The immediate postoperative satisfaction rate at discharge was 95.4% (134/141), and 17.6% (22/125) of patients had the intention to received revision surgery. Conclusions: Prosthesis volume ≥300 ml and peri-areolar incision were independent realtive factors for short-term local complications after bovine pericardium patch combined with prosthesis implantation in the immediate breast reconstruction. After completing the learning curve, the postoperative complications of the procedure could be decreased.
		                        		
		                        		
		                        		
		                        			Adolescent
		                        			;
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Breast Implantation
		                        			;
		                        		
		                        			Breast Implants
		                        			;
		                        		
		                        			Breast Neoplasms/surgery*
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Mammaplasty/methods*
		                        			;
		                        		
		                        			Mastectomy/methods*
		                        			;
		                        		
		                        			Middle Aged
		                        			;
		                        		
		                        			Pericardium/surgery*
		                        			;
		                        		
		                        			Quality of Life
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Young Adult
		                        			
		                        		
		                        	
4.Hand-sewn expanded polytetrafluoroethylene valved conduit for right ventricular outflow tract reconstruction.
Tao QIAN ; Can HUANG ; Ting LU ; Hong ZHANG ; Haoyong YUAN ; Li XIE ; Zhongshi WU
Journal of Central South University(Medical Sciences) 2022;47(1):94-100
		                        		
		                        			OBJECTIVES:
		                        			Due to the lack of large-sized pulmonary valved conduit products in clinical practice, hand-sewn expanded polytetrafluoroethylene (ePTFE) valved conduit has been used for right ventricular outflow tract (RVOT) reconstruction in many heart centers around the world. This study aims to summarize the early results of the ePTFE valved conduit and the sewing technology of the conduit in combination with the latest progress, and to provide a reference for the application of ePTFE valved conduit.
		                        		
		                        			METHODS:
		                        			A total of 21 patients using ePTFE valved conduit for RVOT reconstruction in the Second Xiangya Hospital, Central South University from October 2018 to October 2020 were prospectively enrolled in this study. The age at the implantation of the conduit was 4.3 to 43.8 (median 15.1) years old, with weight of (38.9±4.1) kg. In this cohort, 14 patients underwent re-reconstruction of RVOT, including 12 patients with pulmonary regurgitation at 6.3 to 31.0 (median 13.8) years after tetralogy of Fallot (TOF) repair, and 2 patients with failed bovine jugular vein conduit (BJVC). Seven patients underwent Ross operations. Among them, 3 were for aortic valve stenosis, 2 were for aortic regurgitation, and 2 were for both stenosis and regurgitation. The ePTFE valved conduits were standard hand-sewn during the surgery. The 3 leaflets were equal in size with arc-shaped lower edge of the valve sinus. The free edge of the valve leaflets was straight with the length of about 1 mm longer than the diameter. The height of the valve sinus was 4/5 of the diameter. The junction of the valve leaflet was 3/4 of the height of the sinus. The designed leaflets were then continuous non-penetrating sutured into the inner surface of Gore-Tex vessel to make a valved conduit. Valved conduits with diameter of 18, 20, and 22 mm were used in 2, 9, and 10 cases, respectively. The surgical results, postoperative recovery time, and serious complications were summarized, and the changes of postoperative cardiac function status and hemodynamic status of the conduits were investigated.
		                        		
		                        			RESULTS:
		                        			During the implantation of ePTFE valved conduit for RVOT reconstruction, 2 patients underwent mechanical mitral valve replacement with Ross operation, 2 patients with pulmonary regurgitation with repaired TOF underwent left and right pulmonary artery angioplasty, and 1 patient with failed BJVC underwent tricuspid valvuloplasty. The cardiopulmonary bypassing time for patients underwent re-reconstruction of RVOT was (130.9±16.9) min, with aorta clamping for 1 patient to repair the residual defect of the ventricular septum. The cardiopulmonary bypassing and aorta clamping time for Ross operation were (242.7±20.6) min and (145.6±10.5) min, respectively. The duration of postoperative ventilator assistance, intensive care unit stay, and hospital stay were 3.5 h to 7.7 d (median 17.1 h),11.2 h to 29.5 d (median 1.9 d), and 6.0 to 56.0 (median 13.0) d, respectively. All patients survived after discharge from hospital. The follow-up rate after discharge was 100% with median time at 15.0 (13.0 to 39.0) months. No death happened during the follow-up. One patient underwent stent implantation due to right coronary stenosis 2 months after Ross operation. One patient underwent balloon dilation due to right pulmonary artery ostium stenosis 1 year after re-reconstruction of RVOT. The cardiac function of all patients recovered to NYHA class I 6 months after operation. The peak pressure gradient across the valve measured by transthoracic echocardiography before discharge was (9.4±2.6) mmHg (1 mmHg=0.133 kPa), and (18.3±6.1) mmHg at the last follow-up. There was no significant increase in the gradient during the follow-up (P=0.134). No patient suffered from mild or more pulmonary regurgitation.
		                        		
		                        			CONCLUSIONS
		                        			Hand-sewn ePTFE valved conduit is feasible for RVOT reconstruction. It is a promising material for RVOT reconstruction which can effectively meet clinical need. In our experience, the ePTFE valved conduit is simple to manufacture with satisfactory early outcomes.In the application of ePTFE valved conduit, attention should be paid to implantation indications and postoperative anticoagulation management, especially to the preparation details of the valved conduit, to obtain better function and durability of the conduit after implantation.
		                        		
		                        		
		                        		
		                        			Adolescent
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Constriction, Pathologic/surgery*
		                        			;
		                        		
		                        			Heart Valve Prosthesis/adverse effects*
		                        			;
		                        		
		                        			Heart Valve Prosthesis Implantation/methods*
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Infant
		                        			;
		                        		
		                        			Polytetrafluoroethylene
		                        			;
		                        		
		                        			Prosthesis Design
		                        			;
		                        		
		                        			Pulmonary Valve Insufficiency/surgery*
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Treatment Outcome
		                        			;
		                        		
		                        			Ventricular Outflow Obstruction/surgery*
		                        			
		                        		
		                        	
5.Efficacy of two barrier membranes and deproteinized bovine bone mineral on bone regeneration in extraction sockets: A microcomputed tomographic study in dogs.
Si Wen WANG ; Peng Yue YOU ; Yu Hua LIU ; Xin Zhi WANG ; Lin TANG ; Mei WANG
Journal of Peking University(Health Sciences) 2021;53(2):364-370
		                        		
		                        			OBJECTIVE:
		                        			To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model.
		                        		
		                        			METHODS:
		                        			The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group.
		                        		
		                        			RESULTS:
		                        			The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05).
		                        		
		                        			CONCLUSION
		                        			mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Bone Regeneration
		                        			;
		                        		
		                        			Bone Substitutes
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Dogs
		                        			;
		                        		
		                        			Membranes, Artificial
		                        			;
		                        		
		                        			Minerals
		                        			;
		                        		
		                        			Tooth Extraction
		                        			;
		                        		
		                        			Tooth Socket/surgery*
		                        			;
		                        		
		                        			X-Ray Microtomography
		                        			
		                        		
		                        	
6.Comparison of Different Periodontal Healing of Critical Size Noncontained and Contained Intrabony Defects in Beagles.
Sheng-Qi ZANG ; Shuai KANG ; Xin HU ; Meng WANG ; Xin-Wen WANG ; Tao ZHOU ; Qin-Tao WANG
Chinese Medical Journal 2017;130(4):477-486
BACKGROUNDRegenerative techniques help promote the formation of new attachment and bone filling in periodontal defects. However, the dimensions of intraosseous defects are a key determinant of periodontal regeneration outcomes. In this study, we evaluated the efficacy of use of anorganic bovine bone (ABB) graft in combination with collagen membrane (CM), to facilitate healing of noncontained (1-wall) and contained (3-wall) critical size periodontal defects.
METHODSThe study began on March 2013, and was completed on May 2014. One-wall (7 mm × 4 mm) and 3-wall (5 mm × 4 mm) intrabony periodontal defects were surgically created bilaterally in the mandibular third premolars and first molars in eight beagles. The defects were treated with ABB in combination with CM (ABB + CM group) or open flap debridement (OFD group). The animals were euthanized at 8-week postsurgery for histological analysis. Two independent Student's t-tests (1-wall [ABB + CM] vs. 1-wall [OFD] and 3-wall [ABB + CM] vs. 3-wall [OFD]) were used to assess between-group differences.
RESULTSThe mean new bone height in both 1- and 3-wall intrabony defects in the ABB + CM group was significantly greater than that in the OFD group (1-wall: 4.99 ± 0.70 mm vs. 3.01 ± 0.37 mm, P < 0.05; 3-wall: 3.11 ± 0.59 mm vs. 2.08 ± 0.24 mm, P < 0.05). The mean new cementum in 1-wall intrabony defects in the ABB + CM group was significantly greater than that in their counterparts in the OFD group (5.08 ± 0.68 mm vs. 1.16 ± 0.38 mm; P < 0.05). Likewise, only the 1-wall intrabony defect model showed a significant difference with respect to junctional epithelium between ABB + CM and OFD groups (0.67 ± 0.23 mm vs. 1.12 ± 0.28 mm, P < 0.05).
CONCLUSIONSOne-wall intrabony defects treated with ABB and CM did not show less periodontal regeneration than that in 3-wall intrabony defect. The noncontained 1-wall intrabony defect might be a more discriminative defect model for further research into periodontal regeneration.
Alveolar Bone Loss ; surgery ; Animals ; Biocompatible Materials ; therapeutic use ; Bone Regeneration ; physiology ; Bone Substitutes ; therapeutic use ; Cattle ; Dogs ; Guided Tissue Regeneration, Periodontal ; methods ; Male ; Wound Healing ; physiology
7.Measurement of Intrahepatic Pressure during Microwave Ablation in an Ex Vivo Bovine Liver Model.
Hae Jin KIM ; Hyunchul RHIM ; Min Woo LEE ; Woo Kyoung JEONG
Gut and Liver 2015;9(6):784-790
		                        		
		                        			
		                        			BACKGROUND/AIMS: We experimented with different ablation methods and two types of microwave antennas to determine whether microwave ablation (MWA) increases intrahepatic pressure and to identify an MWA protocol that avoids increasing intrahepatic pressure. METHODS: MWA was performed using either a single-step standard ablation or a stepwise increment ablation paired with either a 16-gauge (G) 2-cm antenna or a 14G 4-cm antenna. We compared the maximum pressures and total ablation volumes. RESULTS: The mean maximum intrahepatic pressures and ablation volumes were as follows: 16G single-step: 37+/-33.4 mm Hg and 4.63 cm3; 16G multistep: 31+/-18.7 mm Hg and 3.75 cm3; 14G single-step: 114+/-45.4 mm Hg and 15.33 cm3; and 14G multistep: 106+/-43.8 mm Hg and 10.98 cm3. The intrahepatic pressure rose during MWA, but there were no statistically significant differences between the single and multistep methods when the same gauge antennae were used. The total ablation volume was different only in the 14G groups (p<0.05). CONCLUSIONS: We demonstrated an increase in intrahepatic pressure during MWA. The multistep method may be used to prevent increased intrahepatic pressure after applying the proper power.
		                        		
		                        		
		                        		
		                        			Ablation Techniques/instrumentation/*methods
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Liver/*physiology/surgery
		                        			;
		                        		
		                        			Medical Illustration
		                        			;
		                        		
		                        			*Microwaves
		                        			;
		                        		
		                        			Models, Animal
		                        			;
		                        		
		                        			*Pressure
		                        			
		                        		
		                        	
8.Efficacy and Safety of Porcine Collagen Filler for Nasolabial Fold Correction in Asians: A Prospective Multicenter, 12 Months Follow-up Study.
Jung Ho LEE ; Yong Sung CHOI ; Sue Min KIM ; Young Jin KIM ; Jong Won RHIE ; Young Joon JUN
Journal of Korean Medical Science 2014;29(Suppl 3):S217-S221
		                        		
		                        			
		                        			Recently, injectable dermal fillers have become important alternatives to surgical procedures for the correction of facial wrinkles. Bovine collagen is the first approved material for filler injection, and several studies have shown its efficacy. However, the risk of developing an allergic reaction and xenogenic transmission of bovine spongiform encephalopathy remain among its disadvantages. In this randomized, double-blinded, split-face study, we compared the efficacy and safety of a porcine collagen filler (TheraFill(R)) with that of a bovine collagen filler (KOKEN(R)) for nasolabial fold correction. A total of sixty one patients with mild to severe nasolabial fold were randomized to receive TheraFill(R) and KOKEN(R) on contralateral sides of the face. During the 12-month follow-up period, improvement in the Wrinkle-Severity Rating Scale score was slightly higher in TheraFill(R) group than KOKEN(R) group, although the difference was not statistically significant. No serious adverse reactions were observed and both materials were tolerable in most cases. In conclusion, the long-term effect of TheraFill(R) on nasolabial fold correction was comparable to that of KOKEN(R), and it may be a good alternative to bovine collagen filler.
		                        		
		                        		
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Aged
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Biocompatible Materials/therapeutic use
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Collagen/adverse effects/*therapeutic use
		                        			;
		                        		
		                        			Dermatologic Surgical Procedures/*methods
		                        			;
		                        		
		                        			Double-Blind Method
		                        			;
		                        		
		                        			Face/surgery
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Follow-Up Studies
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Injections, Intradermal
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Middle Aged
		                        			;
		                        		
		                        			Nasolabial Fold/*surgery
		                        			;
		                        		
		                        			Prospective Studies
		                        			;
		                        		
		                        			Skin Aging
		                        			;
		                        		
		                        			Surgery, Plastic/*methods
		                        			;
		                        		
		                        			Swine
		                        			;
		                        		
		                        			Treatment Outcome
		                        			
		                        		
		                        	
9.Moving-Shot versus Fixed Electrode Techniques for Radiofrequency Ablation: Comparison in an Ex-Vivo Bovine Liver Tissue Model.
Eun Ju HA ; Jung Hwan BAEK ; Jeong Hyun LEE
Korean Journal of Radiology 2014;15(6):836-843
		                        		
		                        			
		                        			OBJECTIVE: To compare the ablation characteristics of the moving-shot technique (MST) and the fixed electrode technique (FET) for radiofrequency (RF) ablation in an ex-vivo bovine liver tissue model. MATERIALS AND METHODS: We performed RF ablation using FET in 110 bovine liver blocks using 11 different ablation times ranging from 5 seconds to 5 minutes (10 blocks per each time duration). Ten bovine liver blocks at each ablation time of 1- or 2-minute, were ablated with MST, which treated conceptual ablation units by moving the electrode tip. We evaluated the ablation volume obtained with FET across ablation time lengths. The results of FET and MST performed with the same ablation time lengths, i.e., 1- and 2-minute ablation time were also compared. RESULTS: The ablation volume achieved with FET gradually increased with increasing ablation time; however, the pair-wise statistical comparison between 2 neighboring ablation time lengths was not significant after 30 seconds. MST with either 1- or 2-minute ablation time achieved larger ablation volumes (1.1 +/- 0.2 mL vs. 2.7 +/- 0.3 mL, p < 0.001; and 1.4 +/- 0.2 mL vs. 5.6 +/- 0.4 mL, p < 0.001, respectively), longer true RF times (46.7 +/- 4.6 seconds vs. 60 seconds, p < 0.001; and 64.8 +/- 4.6 seconds vs. 120 seconds, p < 0.001, respectively), fewer numbers of RF cut-offs (1.6 +/- 0.5 vs. 0, p < 0.001; and 5.5 +/- 0.5 vs. 0, p < 0.001, respectively), and greater energy deposition (2050.16 +/- 209.2 J vs. 2677.76 +/- 83.68 J, p < 0.001; and 2970.64 +/- 376.56 J vs. 5564.72 +/- 5439.2 J, p < 0.001, respectively), than FET. CONCLUSION: The MST can achieve a larger ablation volume by preventing RF cut-off, compared with the FET in an ex-vivo bovine liver model.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Catheter Ablation/*standards
		                        			;
		                        		
		                        			Cattle
		                        			;
		                        		
		                        			Electrodes
		                        			;
		                        		
		                        			Equipment Design
		                        			;
		                        		
		                        			In Vitro Techniques
		                        			;
		                        		
		                        			Liver/*surgery
		                        			;
		                        		
		                        			Models, Biological
		                        			;
		                        		
		                        			Temperature
		                        			
		                        		
		                        	
10.Biomechanical effects of pedicle screw adjustments on the thoracolumbar burst fractures.
Jian SHANG ; Xiao-Dong LING ; Yuan-Chao LIU ; Wei LIU ; Xi-Gang XIAO ; Shao-Hui YUAN
Chinese Medical Journal 2013;126(2):300-305
BACKGROUNDPosterior pedicle screw device is widely used in treatment of thoracolumbar burst fractures. As the clinical operation is not based upon quantitative data of adjustments, the results are not optimal. At present, no study has assessed the associations between the device adjustments and the restoration of stiffness. We investigated the biomechanical effects that adjustments of a pedicle screw device had on the burst fracture, and explored an optimal adjustment.
METHODSBurst fractures were produced at L1 vertebra in 24 fresh calf spines (T12-L3). The specimens were divided into four groups at random. Pedicle screw devices were attached to T13 and L2. Four device adjustments, consisting of distraction and extension, were applied. Adjustment 1 was pure 6° extension, adjustment 2 was pure 5 mm distraction, adjustment 3 was 6° extension followed by 5 mm distraction, and adjustment 4 was 5 mm distraction followed by 6° extension. The effect of each adjustment on the stiffness restoration, anatomical reduction, and neural decompression for the burst fractures was analyzed and evaluated.
RESULTSPure extension (Group 1) produced the closest segment height and the least restoration of the canal to the intact. Pure distraction (Group 2) restored stiffness most, but with only 60% stiffness of the intact value, and lost the segmental angle most to the intact. The combination of extension-distraction (Group 3 and Group 4) produced the maximum reduction of the anatomy and restoration of the canal in the burst fracture, and the least stiffness restoration. The sequence of extension and distraction did not affect stiffness restoration, anatomical reduction, and neural decompression.
CONCLUSIONSThe device adjustments affected stiffness restoration, anatomical reduction, and neural decompression. The combined extension-distraction adjustment may be the most suitable considering the anatomical reduction and neural decompression, but the stiffness decreased the most; it should be considered to reconstruct L1 vertebra.
Animals ; Biomechanical Phenomena ; Cattle ; Female ; Fracture Fixation, Internal ; instrumentation ; Lumbar Vertebrae ; injuries ; surgery ; Male ; Spinal Fractures ; physiopathology ; surgery ; Thoracic Vertebrae ; injuries ; surgery
            
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