Objective To investigate the surgical technique and outcomes of replacement of chordae tendineae in mitral valve repair, and evaluate the value of real-time three-dimensional transesophageal echocardiography in the perioperative period. Methods Thirty-one patients with mitral valve prolapse underwent mitral valve repair using chordae tendineae replacement concomitant with implantation of valveplasty ring. A 4-0 Goretex sutures was used for reconstruction of artificial chordae. Realtime three-dimensional transesophageal echocardiography was performed in all the patients during the preoperative, intraoperatire, and postoperative periods. The length of the chordae tendineae under the A1 section of the anterior leaflet and the P1 section of the posterior leaflet were measured and considered the normal length of chordae tendineae by real-time three-dimensional transesophageal echocardiography preoperatively. These pre-determined normal chordal lengths helped intraoperatively to approximate the length of the artificial chordae used and postoperatively to gauge the success of the procedures. The same values were used again postoperatively to gauge the success of intervention. Full flexible valveplasty rings were used in all the patients.Results There was no operative death. The mean cardiopulmonary bypass (CPB) and aortic cross clamp time were ( 142. 0 ±31.2 ) min and (98.0 ± 22.5 ) min, respectively. One patient' s intraoperative echocardiography upon termination of CPB showed persistent severe mitral regurgitation and was converted to mitral valve replacement. This patient was not included in the study group. The mean number of artificial chordae per patient was (2.0 ± 1.5 ) , range from 1 to 3. The mean preoperatively measured normal chordal length was ( 21.0 ± 2.5 ) mm, and the mean postoperative artificial chordal length was ( 20.0 ± 2.2 )mm. The difference was not significant. The follow-up interval was from 3 to 30 months and the follow-up rate was 98%. During the follow-up period, there was no late death. Trace mitral regurgitation (MR) was detected in 15 patients, mild and moderate MR were detected in 1 for each. No severe MR was detected. The freedom from reoperation was 100% during follow-up.There were no documented artificial chordae ruptures. Conclusion Conclusion Artificial chordal replacement with Gore-tex suture in mitral valve repair in this group of patients with mitral valve prolapse appears to have satisfactory early and mid-term results. Real-time three-dimensional transesophageal echocardiography plays a critical role in this technique. Real-time threedimensional transesophageal echocardiography can exactly predict the length of artificial chordae, which is helpful to improve the outcomes of mitral valve repair. However, longer term follow-up and larger series are required to validate our findings.

Objective:To compair the clinical effect of endoscopic spine surgery with and without assistance of an electromagnetic navigation surgical robot(ENSR) system in the treatment of lumbar disc herniations(LDH).Methods:From March 2021 to December 2021, 73 patients with LDH underwent endoscopic minimally invasive treatment in the Department of Spine Surgery, Limin Hospital of Weihai High District. Thirty-eight patients were treated with endoscopic spine surgery assisted by domestic ENSR system(ENSR group), and 35 patients were treated with endoscopic spine surgery alone(endoscopic group). The patients received follow up regularly by telephone or Wechat. The intraoperative fluoroscopy times, puncture times, upper facet arthroplasty times, operation time, preoperative and postoperative Visual Analogue Scale(VAS), Japanese Orthopaedic Association Scores(JOA), and the MOS item short from health survey(SF-36)were compared between the 2 groups. The early postoperative efficacy was evaluated by modified MacNab criteria at 1 week after surgery. SPSS 26.0 was used to analyse the data. P<0.05 was considered that the difference was statistically significant. Results:The age, gender, body mass index(BMI) and other general data of the 2 groups were basically the same, and there was no statistically significant difference( P>0.05). There was no significant difference in the excellent and good rate of postoperative treatment between ENSR group(97.37%) and endoscopic group(94.29%)( Z=0.90, P>0.05). In terms of operation time, intraoperative fluoroscopy times, puncture times, and plasty times, ENSR group[(67.00±17.00) min, (4±2) times, 1 time, 1 time, respectively] was compared with the endoscopic group[(82.00±16.00] min, (17±6) times, (9±5) times, (5±2) times], and the difference was statistically significant( t=3.87,12.62, 9.87, respectively, P<0.05). There were significant differences in VAS, JOA and SF-36 scores between the 2 groups between before and after surgery( F=106.42, 112.14, 26.88, respectively, P<0.05). There was no significant difference in VAS, JOA and SF-36 scores before and after surgery between the 2 groups( F=0.95, 3.54, 0.97, respectively, P>0.05). Conclusion:The endoscopic spine surgery assisted by the ENSR can achieve satisfactory clinical results and is a safe and effective surgical assistance system. For the endoscopic surgery, assisted by the ENSR has obvious advantages in reducing the times of fluoroscopy, puncture, and facet arthroplasty, and shortening the operation time.

Objective:To compare the early therapeutic effects of internal fixation with percutaneous minimally invasive hollow nail assisted by electromagnetic navigation robot and guided by C-arm in the treatment of Tile type C pelvic fracture.Methods:A retrospective cohort study was conducted to analyze the clinical data of 32 patients with Tile type C pelvic fracture admitted to Weihai Central Hospital from January 2020 to March 2022, including 18 males and 14 females; aged 36-60 years [(44.1±3.9)years]. Among them, 17 patients were treated with internal fixation with percutaneous minimally invasive hollow nail assisted by electromagnetic navigation robot (electromagnetic navigation group), and 15 with internal fixation with percutaneous minimally invasive hollow nail guided by C-arm (C-arm guidance group). Operative time, intraoperative blood loss, sacroiliac screw placement time, pubic branch screw placement time, ambulation time and fracture healing time were compared between the two groups. Visual analog scale (VAS), Majeed function score and complication rate at 1 day, 6 months, 12 months after surgery and at the last follow-up were compared between the two groups.Results:All the patients were followed up for 12-24 months [(15.4±0.5)months]. The operative time and intraoperative blood loss in the electromagnetic navigation group were (42.0±2.5)minutes and (10.9±2.6)ml, shorter or less than (50.0±3.5)minutes and (14.9±3.1)ml in the C-arm guidance group (all P<0.01). The placement time of sacroiliac screw and pubic branch screw in the electromagnetic navigation group was (12.4±0.2)minutes and (10.1±0.3)minutes, shorter than (15.3±0.3)minutes and (13.2±0.3)minutes in the C-arm guidance group (all P<0.01). The ambulation time was (3.2±0.4)weeks in the electromagnetic navigation group, earlier than (3.5±0.4)weeks in the C-arm guidance group ( P<0.05). There was no significant difference in fracture healing time between the two groups ( P>0.05). VAS scores of the electromagnetic navigation group were (4.4±0.3)points and (1.1±0.1)points at 1 day and 6 months after surgery respectively, lower than those of the C-arm guidance group [(4.8±0.4)points and (1.2±0.3)points] ( P<0.05 or 0.01). Majeed function scores of the electromagnetic navigation group were (37.3±1.1)points and (88.5±1.4)points at 1 day and 6 months after surgery respectively, higher than those of the C-arm guidance group [(30.7±4.2)points and (82.6±1.8)points] (all P<0.01). There were no significant differences in VAS and Majeed scores at 12 months after surgery and at the last follow-up between the two groups (all P>0.05). There was no significant difference in the incidence of postoperative complications between the two groups ( P>0.05). Conclusion:Compared with C-arm guidance, electromagnetic navigation robot-assisted internal fixation with percutaneous minimally invasive hollow nail for Tile type C pelvic fracture can reduce operative time and intraoperative blood loss, shorten screw placement time and ambulation time, relieve pain and improve functional recovery at early stage.