Aiming at the cropping operations widely applied in practical industry production, a new method of bar cropping is presented. The rotational speeds of actuating motor of eccentric blocks are controlled by a frequency-changer, and the shearing die provides the bar with the controllable force, frequency and amplitude of vibration. By utilizing the stress concentration at the bottom of V shape groove on the bar, the low stress bar cropping is realized. The bar cropping experiments of duralumin alloy and steel show that the shear surface has no radial distortion and deviation angle, the cutting force is lower and the die life is longer compared with the common bar cropping method. According to the special feature of cutting surface obtained by the new method, a new method of measurement is proposed and applied to assess the cutting surfaces obtained by the different control curves of frequency. The results show that the linear decrease control method is the best.

Objective To investigate whether the laparoscopic portoenterostomy is superior to open surgery in the treatment of biliary atresia.Methods A total of 26 children with type Ⅲ biliary atresia underwent laparoscopic portoenterostomy from August 2003 to September 2005(Laparoscopic Group).The operation was performed under 4-port laparoscopy.The hepatic portal was fully exposed and mobilized and the gallbladder was removed.The cut end of the duct was widened by incising along the anterior wall of the hepatic duct following the excision of the narrow segment.By using intraoperative bile duct endoscopy,the optimal level of resection of the common hepatic duct was determined without endangering the orifices of the hepatic ducts or leaving any redundant duct.The Roux-en-Y jejunal loop was fashioned extracorporeally by exteriorizing the jejunum for 40 cm in length distally through the umbilical incision and passed up retrocolically followed by an end-to-side hepaticojejunostomy.They were compared with other group of 34 children,with the same age range and diagnosis,who underwent open portoenterostomy(Open Group) in the same period,in respect of the operative time,the blood loss,the liver functions,complications,the length of hospital stay,the hospitalization expenditure,and the short-term outcomes. Results As compared with the Open Group,the Laparoscopic Group presented a less blood loss(15.4?5.0 ml vs 33.8?19.4 ml;t=-4.709,P=0.000) and a higher hospitalization expenditure(19 153.9?619.5 yuan vs 15 116.7?898.4 yuan;(t=19.607),P=0.000).There were no significant differences between the two groups in the operative time and the length of hospital stay.The serum levels of total bilirubin,direct bilirubin,ALT,and AST were deceased more significantly in the Laparoscopic Group than in the Open Group.Complications happened in 1 case in the Laparoscopic Group(incisional hernia) and in 4 cases in the Open Group(1 case of acute hepatic failure,1 case of incision rupture,and 2 cases of wound infection),the incidence of complications being not significant(?~2=0.395,P=0.530).Follow-up observations at 4 postoperative month found the jaundice had subsided in 13 cases in the Laparoscopic Group(50%) and in 18 cases in the Open Group(53%). Conclusions Laparoscopic portoenterostomy is a minimally invasive,safe,and effective procedure for the treatment of pediatric biliary atresia.

Objective To explore the categories and precautions of complications after laparoscopic total cyst excision with Roux-en-Y hepatoenterostomy for congenital choledochal cyst in children. Methods Laparoscopic cyst excision with Roux-en-Y hepatoenterostomy was performed in 66 cases of congenital choledochal cyst from July 2001 to June 2006. Their median age was 3.8 years (range, 2 months ~ 28 years). The choledochal cyst was classified as cystic type in 61 cases, with a diameter ranged 2.5~18 cm, and fusiform type in 5 cases, with a diameter ranged 1.2~2.2 cm. Nine cases were associated with hepatic ductal stenosis; they underwent a laparoscopic excision of the cyst with a ductoplasty. Results The laparoscopic operation was successfully completed in all the 66 patients, with a mean operation time of 3.8 h (2.6~9.5 h) and a mean hospital stay of 4.5 d (3~8 d). Early complications included 2 cases of bile leakage (spontaneous recovery in 1 case, and an open surgery required in 1 case because of obstructed drainage, with anastomotic leakage identified and re-anastomosis performed during the operation), 1 case of hyperkalemia (10.8 mmol/L at 7 h after operation, resulting in heart failure and cardiopulmonary resuscitation, and died of renal failure on the 3rd postoperative day), and 2 cases of stress ulcer (spontaneously relieved). There were no infections of the abdominal cavity or the wound. Long-term complications included 1 case of intestinal obstruction (open exploration showed intestinal adhesion and necrosis, and an enterectomy with enteroanastomosis was given). No anastomotic stenosis and postoperative cholangitis were encountered.Follow-up observations for 6~56 months (median, 21 months) were conducted in 65 survived cases, B-ultrasonography found no bilestone, and liver functions were in normal limits. Conclusions Laparoscopic total cyst excision with Roux-en-Y hepatoenterostomy is a complicated operation with high risks. Some complications are similar to those after conventional operations, such as bile leakage, stress ulcer, and intestinal obstruction. Hyperkalemia is perhaps the most serious one, which maybe related to carbon dioxide pneumoperitoneum. It is essential to monitoring hyperkalemia in postoperative period.

Objective To compare the surgical and functional outcomes of single-site (transumbilical two-port) intracorporeal purse-suturing (IP) and single-port extracorporeal knotting (EK) for laparoscopic pediatric inguinal hernia (PIH) repair.Methods Between June 2008 and December 2014,358 PIH children underwent lapamscopic inguinal herniorrhaphy,including 126 treated by single-site intracorporeal purse string stitching using a needle-holder (IP group),and 232 by single-port extracorporeal knotting using an inner two-hook needle with preperitoneal hydrodissection (EK group).Results In all patients laparoscopic procedures were completed successfully without conversion.The operating time in IP group was significantly longer than that in EK group [unilateral:(20.4 ± 2.1) min vs.(9.4 ± 1.3) min,t=-5.23,P＜0.01;bilateral:(31.3 ±2.9) min vs.(15.2±1.7) min,t=-4.22,P＜0.01)].The hospital stay were similar between the two groups [(2.35 ±0.25) d vs.(2.38 ±0.18) d,t =-0.062,P ＞ 0.05].Five cases had intraoperative hematoma in the IP group while none in the EK group.One each suffered from recurrence in IP group and EK group.Three postoperative hydroceles were seen in IP group and one in EK group.Subcutaneous knot granulomas were seen in two in EK group.Conclusions Both IP and EK laparoscopic procedures are safe and feasible.With the assistance of preperitoneal hydrodissection technique,single-port laparoscopic EK herniorraphy is superior to single-site IP repair in easy performance and shorter operation time.

Objective:To study the risk factors for ipsilateral severe hearing impairment in patients with hemifacial spasm (HFS) after microvascular decompression (MVD).Methods:MVD was performed in 3700 patients with HFS, admitted to our hospital from October 2007 to August 2020; according to the existence of ipsilateral severe hearing impairment, these patients were divided into severe hearing impairment group and non-severe hearing impairment group. The clinical data of these patients were compared. Multivariate linear regression analysis was used to determine the independent influencing factors for ipsilateral severe hearing impairment.Results:Forty-five patients (1.2%) had ipsilateral severe hearing impairment after MVD; no one got recovery of hearing impairment during the follow-up period (0.6-11.8 years, 6.3 years in average). As compared with those in the non-severe hearing impairment group, patients in the severe hearing impairment group had significantly older age, significantly higher percentages of male patients, and patients with left HFS, hypertension, and diabetes mellitus, statistically higher percentage of patients having small posterior fossa volume, arachnoid thickening and adhesion, and vertebral artery compression, significantly lower percentage of patients with anterior inferior cerebellar artery compression, significantly higher percentage of patients with arteriosclerosis of offending arteries and difficult decompression ( P<0.05). Multivariate linear regression analysis revealed that hypertension, vertebral artery compression, arteriosclerosis of offending artery and difficult decompression were independent risk factors for severe hearing impairment in patients with HFS after MVD. Conclusion:It's difficult to get recovery for severe hearing impairment in patients with HFS after MVD; this complication is much common in patients with hypertension, vertebral artery compression, arteriosclerosis of offending artery or difficult decompression.

Objective To investigate the safety and effectiveness of transumbilical repair for hernia of linea alba within 3 cm above the umbilicus.Methods Clinical data of 26 patients who underwent transumbilical approach hernia repair in our hospital from June 2016 to July 2022 were retrospectively analyzed.Color ultrasound examination showed that the distance from the lower edge of the hernia to the upper edge of the umbilicus was≤3 cm.The hernia repair was performed through the fascial space via the upper edge approach of the umbilical ring.There were 7 boys and 19 girls.The age was 7 months to 11 years old(median,3 years old).The distance from the lower edge of the hernia sac to the upper edge of the umbilicus was(1.46±0.66)cm,and the diameter of the hernia of linea alba was(1.16±0.57)cm.Results The surgery was completed smoothly.The operation time was(39.1±26.3)min.No complication was noted.All the patients were discharged one day after surgery.The follow-ups lasted for 1 year and 2 months to 7 years and 3 months(median,5 years and 1 month).No wound infection,bleeding or other complications occurred.No recurrence of hernia or formation of skin granulomas happened.Conclusion Transumbilical approach repair for hernia of linea alba within 3 cm above the umbilicus is safe and effective,with good cosmetic results.

Objective:To investigate the factors related to child care environment and the association between child care environment and children′s early development.Methods:Using stratified cluster random sampling, a total of 22 509 children newly enrolled to kindergarten from 187 kindergartens of 16 districts in Shanghai in 2017 were enrolled. A survey was conducted by parent-reported questionnaire. The index of child care environment (ICCE) and the early human capacity index were used to evaluate family child care environment and children′s early development respectively. The sample was divided into four groups based on the ICCE score: the lowest family childcare environment (ICCE≤10 scores), lower middle (ICCE=11 scores), upper middle (ICCE=12 scores), and the highest (ICCE=13 scores). The linear regression model and Logistic regression model were used to analyze the factors related to child care environment and the association between child care environment and children′s early development respectively.Results:A total of 22 067 children aged (44±7) months, including 11 425 boys (51.8%) and 10 642 girls (48.2%), participated in this study. The multnomial linear regression revealed girls, higher maternal education, higher household annual income, single-child, non-divorced parents, and early breastfeeding experience were protective factors of child care environment for children newly enrolled to kindergarten ( β=0.064, 0.238, 0.119, 0.096, 0.113, and 0.032; 95% confidence interval ( CI): 0.020-0.108, 0.175-0.302, 0.058-0.180, 0.046-0.146, -0.012-0.242, and -0.051-0.116; all P<0.01). The multinomial Logistic regression revealed compared with the highest child care environment group, the odds ratio of children′s early development risks in upper midclle, lower middle, and the lowest child care environment groups were 1.543 (95% CI: 1.373-1.735, P<0.01), 2.537 (95% CI: 2.254-2.856, P<0.01), and 4.198 (95% CI: 3.757-4.690, P<0.01), respectively. Conclusions:The child care environment is not only significantly related to family structure and socioeconomic status, but also to early breastfeeding experience. The child care environment plays an important role in promoting childhood early development.

Objective:To compare the effect of temporal external fixator and digital guide plate in the immediate reconstruction of mandibular defect after segmental mandibulectomy.Methods:The clinical data of all patients who received segmental mandibulectomy and immediate mandibular reconstruction with free vascularized bone graft by a single surgical team in the Department of Oral & Maxillofacial-Head & Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from August 2016 to December 2017 were retrospectively analyzed. According to different auxiliary methods, the patients were divided into temporal external fixator (TEF) group and computer aided design-manufacture (CAD-CAM) group. The width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were measured by CT before and one month after surgery, and the difference before and after surgery was calculated to evaluate the surgical effect. SPSS 19.0 was used for statistical analysis, and the data were expressed as Mean ± SD. Independent sample t-test was used for comparison of indexes of surgical time and surgical effect evaluation between the two groups, and P<0.05 indicated statistically significant differences. Results:A total of 29 patients were enrolled, including 13 patients in TEF group, 4 males and 9 females, aged (47.7±14.5) years, including 7 ameloblastomas, 2 squamous cell carcinomas, 2 abnormal proliferation of bone fibers, 1 rhabdomyosarcoma and 1 osteosarcoma. In the CAD-CAM group, there were 16 cases, including 11 males and 5 females, aged (42.4±19.7) years, including 10 ameloblastomas, 3 squamous cell carcinomas, 1 osteoblastoma, 1 otogenic fibromyxoma and 1 osteosarcoma. The bone grafts in 29 patients were all alive, the wounds healed primarily, and the occlusal relationship and facial contour of the patients were fine. After 3 years follow-up, there were no postoperative complications and tumor recurrence. The function of the supply area was not affected. The operative time was (7.12±1.40) h in the TEF group and (4.72±1.10) h in the CAD-CAM group, and the difference between the two groups was statistically significant ( P<0.01). In the TEF group, the difference of the width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were (1.08±1.12) mm, (2.08±1.61) mm, (1.77±3.15) mm, respectively; CAD-CAM group were (0.88±1.15) mm, (0.94±1.34) mm, (0.87±1.47) mm, respectively, and there was no statistical significance between the two groups ( P>0.05). Conclusions:It took significantly longer to perform immediate mandibular reconstruction assisted by TEF than that assisted by CAD-CAM in surgery, but both groups achieved better surgical results. It is simpler and more effective to use TEF when time is urgent or technology is too limited to carry out preoperative digital design.

Objective:To compare the effect of temporal external fixator and digital guide plate in the immediate reconstruction of mandibular defect after segmental mandibulectomy.Methods:The clinical data of all patients who received segmental mandibulectomy and immediate mandibular reconstruction with free vascularized bone graft by a single surgical team in the Department of Oral & Maxillofacial-Head & Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from August 2016 to December 2017 were retrospectively analyzed. According to different auxiliary methods, the patients were divided into temporal external fixator (TEF) group and computer aided design-manufacture (CAD-CAM) group. The width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were measured by CT before and one month after surgery, and the difference before and after surgery was calculated to evaluate the surgical effect. SPSS 19.0 was used for statistical analysis, and the data were expressed as Mean ± SD. Independent sample t-test was used for comparison of indexes of surgical time and surgical effect evaluation between the two groups, and P<0.05 indicated statistically significant differences. Results:A total of 29 patients were enrolled, including 13 patients in TEF group, 4 males and 9 females, aged (47.7±14.5) years, including 7 ameloblastomas, 2 squamous cell carcinomas, 2 abnormal proliferation of bone fibers, 1 rhabdomyosarcoma and 1 osteosarcoma. In the CAD-CAM group, there were 16 cases, including 11 males and 5 females, aged (42.4±19.7) years, including 10 ameloblastomas, 3 squamous cell carcinomas, 1 osteoblastoma, 1 otogenic fibromyxoma and 1 osteosarcoma. The bone grafts in 29 patients were all alive, the wounds healed primarily, and the occlusal relationship and facial contour of the patients were fine. After 3 years follow-up, there were no postoperative complications and tumor recurrence. The function of the supply area was not affected. The operative time was (7.12±1.40) h in the TEF group and (4.72±1.10) h in the CAD-CAM group, and the difference between the two groups was statistically significant ( P<0.01). In the TEF group, the difference of the width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were (1.08±1.12) mm, (2.08±1.61) mm, (1.77±3.15) mm, respectively; CAD-CAM group were (0.88±1.15) mm, (0.94±1.34) mm, (0.87±1.47) mm, respectively, and there was no statistical significance between the two groups ( P>0.05). Conclusions:It took significantly longer to perform immediate mandibular reconstruction assisted by TEF than that assisted by CAD-CAM in surgery, but both groups achieved better surgical results. It is simpler and more effective to use TEF when time is urgent or technology is too limited to carry out preoperative digital design.