Objective To explore the efficacy of extracting biopsy needle pose in chest CT images based on point cloud processing.Methods Three-dimensional point clouds were generated through segmentation of chest CT images and surface reconstruction.Spatial point cloud clustering and geometric constraints were applied to filter regions contained the puncture needle in space.The principal direction of the needle was judged using principal component analysis,and a cylindrical model was constructed to enclose the needle data.Then random sample consensus algorithm was used for needle trajectory fitting to accurately extract the spatial position and orientation of the puncture needle.The efficacy of the above method was evaluated using a 3D-printed anatomical model based on common clinical combinations of puncture depths and angles.Results The anatomical model experiments showed a 100％success rate in puncture needle identification,with angular error of(1.013±0.424)° and positional error of(2.023±1.553)mm,indicating that this method had good accuracy and stability.Conclusion The puncture needle's position in chest CT images could be extracted with high precision based on point cloud processing.

Objective To explore the efficacy of extracting biopsy needle pose in chest CT images based on point cloud processing.Methods Three-dimensional point clouds were generated through segmentation of chest CT images and surface reconstruction.Spatial point cloud clustering and geometric constraints were applied to filter regions contained the puncture needle in space.The principal direction of the needle was judged using principal component analysis,and a cylindrical model was constructed to enclose the needle data.Then random sample consensus algorithm was used for needle trajectory fitting to accurately extract the spatial position and orientation of the puncture needle.The efficacy of the above method was evaluated using a 3D-printed anatomical model based on common clinical combinations of puncture depths and angles.Results The anatomical model experiments showed a 100％success rate in puncture needle identification,with angular error of(1.013±0.424)° and positional error of(2.023±1.553)mm,indicating that this method had good accuracy and stability.Conclusion The puncture needle's position in chest CT images could be extracted with high precision based on point cloud processing.

Objective:To investigate the safety and efficacy of indignant jejunostomy tube in radical resection of gastric carcinoma.Methods:Using "radical gastrectomy, esophagectomy, jejunostomy, enteral nutrition" as the Chinese search terms and "gastrectomy, esophagectomy, jejunostomy, jejunostomies, enteral nutrition" as the English search terms searched Pubmed, MEDLINE, EMbase, Web of Science, Cochrane Library, CNKI, VIP, Wanfang and CBMdisc. The Chinese and English literatures published at home and abroad on indwelling and non-indwelling jejunostomy tubes after radical resection of gastric carcinoma from January 2010 to December 2020 were collected, including randomized controlled trial and cohort studies. The main outcome measure was the length of hospital stay; the secondary outcome measure was the overall postoperative complication rate, postoperative pulmonary infection rate, intestinal obstruction rate, and body weight changes at 3 and 6 months after radical gastrectomy. Meta-analysis was conducted using RevMan 5.2 software.Results:Finally, 12 articles with a total of 2 173 patients were included. Compared with the non-indwelling jejunostomy tube group, the patients in the indwelling group had a longer hospital stay ( WMD=2.05, P=0.01) and a higher incidence of intestinal obstruction ( OR=11.67, P<0.001). The incidence of overall postoperative complications ( OR=1.24, P=0.31), the incidence of postoperative pulmonary infection ( OR=1.43, P=0.13) and 3 months after radical gastrectomy ( WMD=0.58, P=0.24), 6 months ( P>0.05), the difference were not statistically significant. Conclusions:Indwelling jejunostomy tube placement after radical gastrectomy of gastric carcinoma did not show more therapeutic advantages, but prolonged the length of hospital stay and the probability of intestinal obstruction. Therefore, selective jejunostomy tube placement rather than routine jejunostomy placement should be required.

Objective:To investigate the short term efficacy of laparoscopic assisted transanal total mesorectal excision (taTME) for low rectal cancer.Methods:The prospective study was conducted. The clinicopathological data of 80 patients who underwent laparoscopic assisted taTME for low rectal cancer in 8 medical centers，including 27 cases in the First Affiliated Hospital of Jilin University，16 cases in the Daping Hospital of Army Medical University，15 cases in the Beijing Friendship Hospital of Capital Medical University，10 cases in the Peking University Cancer Hospital，7 cases in the Peking Union Medical College Hospital of Chinese Academy of Medical Sciences，2 cases in the Peking University People′s Hospital，2 cases in the Liaoning Cancer Hospital Institute，1 case in the Ruijin Hospital of Shanghai Jiaotong University School of Medicine，from August 2017 to September 2018 were collected. Observation indicators：(1) clinical data of enrolled patients；(2) surgical situations；(3) postoperative histopathological examination；(4)postoperative complications and hospitalization. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers and (or) percentages. Results:(1) Clinical data of enrolled patients：a total of 80 patients were selected for eligibility. There were 59 males and 21 females，aged from 53 to 79 years，with a median age of 61 years. (2）Surgical situations：all 80 patients underwent surgery successfully，including 73 cases undergoing low anterior resection，4 cases undergoing Hartmann operation，1 case undergoing intersphincteric and abdominoperineal resection，1 case undergoing other operations and 1 case missing operation information. Nineteen of the 80 patients underwent transabdominal and transanal operations simultaneously. The operation time of 80 patients was 255 minutes (range，211?305 minutes). Of 80 patients，77 cases had the volume of intraoperative blood loss ≤500 mL，3 cases had the volume of intraoperative blood loss >500 mL，44 cases underwent instrumental anastomosis，24 cases underwent manual anastomosis，12 cases were missing anastomosis information，66 cases had specimens been taken out through anus，2 cases had specimens been taken out through Pfannens-tiel incision，10 cases had specimens been taken out through other ways，2 cases were missing the information of specimens removal ways，57 cases underwent preventive stoma，32 cases under-went anal canal indwelling，30 cases underwent free of splenic flexure and 2 cases were converted to open surgery. (3) Postoperative histopathological examination：of 80 patients，68 cases had the integrity of mesorectal specimens with complete，5 cases had the integrity of mesorectal specimens with near complete，1 case had the integrity of mesorectal specimens with not complete，6 cases were missing the information of integrity of mesorectal specimens，1 case had rectal perforation，1 case had positive circumferential margin and 1 case had positive distal margin. The number of lymph node dissected and diameter of tumor were 12(range，9?16) and 3.0 cm(range，1.9?4.0 cm) of 80 patients. Four of 80 patients achieved pathological complete remission. Cases with tumor stage as T0 stage，Tis stage，T1 stage，T2 stage，T3 stage or T4 stage of the pT staging，cases with tumor stage as N0 stage，N1 stage or N2 stage of the pN staging，cases with tumor stage as M0 stage or M1 stage of the pM staging were 4，2，11，24，35，4，55，21，4，75，5 of 80 patients. (4) Postopera-tive complications and hospitalization：8 of 80 patients underwent anastomotic leakage，including 2 cases with grade A anastomotic leakage，4 cases with grade B anastomotic leakage and 2 cases with grade C anastomotic leakage.Seven of 80 patients underwent intestinal obstruction. The 2 cases with grade A anastomotic leakage were improved after symptomatic drug treatment，the 4 cases with grade B anastomotic leakage were improved after treatment with antibiotics or catheter drainage and the 2 cases with grade C anastomotic leakage were improved after operation. The duration of hospital stay of 80 patients was 14 days(range，11?21 days). No patient died during hospitalization.Conclusion:Laparoscopic assisted taTME for low rectal cancer is safe and feasible，which has a good short term efficacy.