Objective:To evaluate the efficacy of angioplasty on percutaneous superior vena cava occlusion in hemodialysis patients with tunnel-cuffed catheter (TCC) under digital subtraction angiography (DSA) guidance.Methods:A total of 62 hemodialysis patients with TCC in the First Affiliated Hospital of Sun Yat-sen University from December 2017 to June 2020 were enrolled retrospectively. According to the patency of the superior vena cava, the patients were divided into experiment group ( n=20) and control group ( n=42) in this study. Hemodialysis patients with superior vena cava occlusion in the experiment group received angioplasty, including balloon angioplasty, stenting and sharp recanalization, and catheterization with TCC under DSA guidance, while hemodialysis patients without superior vena cava occlusion in the control group only underwent catheterization with TCC under DSA guidance. The 1-year TCC patency rate, postoperative TCC blood flow and treatment-related complications between the two groups were compared. Results:In the experiment group, a total of 11 patients were treated only by percutaneous transluminal angioplasty, while 9 patients were treated combined percutaneous transluminal angioplasty with stent placement. In addition, 3 patients underwent sharp recanalization of superior vena cava occlusion. A total of 9 stents and 29 balloons were used. The course of dialysis in experiment group was longer than that in control group ( P<0.05). There were no significant differences in the 1-year TCC patency rate (85.0% vs 95.2%, P>0.05), postoperative TCC blood flow [(257.83±16.55) ml/min vs (251.90±18.79) ml/min, P>0.05] and incidence of treatment-related complications (grade 1-2, 30.0% vs 35.7%, P>0.05) between the two groups, respectively. Patients in the two groups had none of serious operation-related complications, and only some patients had mild clinical manifestations, such as postoperative pain and bleeding at the puncture point. Conclusions:For patients with longer duration of hemodialysis and superior vena cava stenosis and occlusion treated with angioplasty, the clinical effect of TCC within one year is equivalent to that of hemodialysis patients without angioplasty.

Objective To investigate the anatomy characteristics of saphenous artery(SA) and its perforator vessels in mini pig,and to provide a new perforator flap animal model.Methods Between May,2018 and August,2018,6 7-months-old mini pigs weight 25 kilograms were sacrificed by blooding under general anesthesia.The bilateral external iliac arteries were injected with a mixture of latex-lead oxide mixture and underwent CT-scanning to provide 3-dimensional reconstruction.The origin,diameter,courses and distribution of the SA and perforators of both hind limbs were observed.Results One of the hind limbs was abandoned due to the leakage of perfusion fluid.The other 11 hind limbs were available.The femoral artery passed through the medial femoral muscle and sartorius muscle in the middle of thigh,and run between the medial femoral muscle and gracilis muscle above the knee.Below the knee,it run on the surface of the medial leg muscles.A number of small branches were distributed in the tarsal joint and calcaneus at the medial malleolus,and there were abundant communicating branches with the posterior tibial artery.The average length of SA was (14.86±0.76) mm.The outer diameters of SA at initiative,medial tibial condyle and medial malleolus were(1.73±0.15) mm,(1.50±0.12) mm and (1.30±0.13) mm,respectively.There were a total of 79 perforators which were identified,with a mean of (7.09±1.16) perforators per hind limbs.And the average outer diameter was 0.10-0.78 (0.40±0.13) mm.Conclusion The SA constantly exist with good outer diameter.The number of perforator is abundant.SA can be used as a reliable animal model for studying and training of perforator flap.

[Objective] To observe the effect of computer-aided detection (CAD) system in improving lung nodule detection sensitivity and inter-observer variation.[Methods] 300 PA digital radiographs including 100 normal cases and 200 cases with pulmonary nodules confirmed by CT were enrolled.Two senior chest radiologists referenced CT images and marked the sizes and locations of all nodules with consensus as the gold standards.Four senior radiologists and four junior radiologists interpreted the digital chest radiographs independently without and with CADand recordtheir results.Pair t test and coefficient of variation (CV) was used to compare the difference of lung nodule detection sensitivity and inter-observer variation between withoutand with CAD.[Results] The mean lung nodule detection sensitivity of senior and junior radiologists withoutand with CAD were (41.1 ± 2.0)％,(28.0 ± 2.0)％ and (45.0 ± 1.8)％,(39.2 ± 0.9)％,respectively,statistical analysis showed there was statistically significant difference.Moreover,CV of all radiologists without and with CAD were 20.9％ and 8.1％.[Conclusion] Both lung nodule detection sensitivity and inter-observer variation of senior and junior radiologists can be improved by CAD.

[Objective] To investigate the clinical value of using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and dose technology.[Methods]A total of 60 patients (heart rate≤ 75 bpm and normal heart rhythm) with suspected aortic disease or post-operation were randomly divided into 2 groups:G1 (n =30;tube voltage:80 kV;contrast medium injection rate:3 mL/s;contrast medium dose:0.65 mL/kg)and G2 (n =30;tube voltage:120 kV;contrast medium injection rate:4 mL/s;contrast medium dose:1.2 mL/kg).The two groups underwent aorta angiography with prospective ECG-gating Helical protocol by using 320-detector CT.The mean CT values and standard deviation of aorta,coronaries and adjacent adipose tissue were measured,signal to noise ratio (signal-to-noise ratio,SNR)and contrast to noise ratio (contrast-to-noise ratio,CNR) were calculated.The subjective quality scoring of 3-d post-processing images were evaluated independently by 2 senior radiologists.The mean CT values and standard deviation of aorta,coronaries and adipose tissue,SNR,CNR,subjective quality scoring,contrast medium dose and radiation dose were compared and analyzed.[Results] The abnormal and normal rate of aorta in two groups were 83.33％ (25/30),16.67％ (5/30) and 86.67％ (26/30),13.33％(4/30);while the abnormal and normal rate of coronary arteries in two groups were 43.33％ (13/30),56.67％ (17/30) and 53.33％(16/30),46.67％ (14/30).SNR values of ascending aorta,descending aorta,abdominal aorta,superior mesenteric artery,bilateral renal artery,left main coronary artery,left anterior descending branch,left circumflex branch,right coronary artery and CNR values of abdominal aorta,superior mesenteric artery,bilateral renal artery,left anterior descending branch,left circumflex branch had no statistical significance,while the other indicators were significant differences between the two groups.The radiation dose and the contrast medium dose of G1 was significantly lower than G2 (P ＜ 0.05).There was no difference in the subjective image quality of 3D post-processing images between the two groups (P ＞ 0.05).[Conclusions] Using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and low contrast medium dose technology can help to reduce radiation and contrast medium dose without impacting on the imaging quality satisfactorily.

Objective To investigate the effect of perforator identification before DIEP flap dissection for the patient with abdominal scar.Methods Preoperative multidetector-row computed tomography angiography was used to identify that the dominant perforators of the abdominal wall were not damaged completely.During the second stage breast reconstruction operation,the located dominant perforator and the DIEP flap were dissected.Results The dominant perforator located by MDCTA was identified with the exploration in operation.Follow-up for half a year,the flap survived well and the patient was satisfied with the appearance.Conclusion Abdominal scar was not the definite contraindication for DIEP flap.MDCTA provided a good quality evaluation of the perforator vessels.The located dominant perforator was dissected to confirm the blood supply of the DIEP flap.Identification of perforator can be used as a routine preoperative evaluation for patients with scar on donor site.

Objective To evaluate the results and complications of hip arthroplasty performed as a salvage procedure after the failed treatment of intertrochanteric hip fractures in elderly patients. Methods Between 2004 and 2009,10 patients were treated with hip arthroplasty after the failed treatment of intertrochanteric fracture.There were six females and four males,at mean age of 75.7 years ( range,68-84 years).The initial treatment of fractures included dynamic hip screw (DHS) fixation in three cases,dynamic condyle screw (DCS) fixation in one,proximal femur fixation with reconstruction interlocking nail in three and conservative treatment without internal fixation in three.The failed procedures included avascular necrosis in four cases,cephalic implant cutting in three,nonunion in two and malunion associated with osteoarthritis in one.Joint hip replacement was performed except for pre-operative infection.Harris score at follow-up was recorded and prosthesis position was evaluated by imaging. Results Six patients were treated with total hip arthroplasty with a cemented cup (three patients) and an uncemented cup ( three patients) and four with a bipolar hemiarthroplasty.A long-stem implant was used in 5 of the 10 hips.The average duration of follow-up was 4.6 years (2-7 years).The mean duration of surgery was 128 minutes and mean blood loss was 764 ml.The mean Harris hip score increased from 37 preoperatively to 85 postoperatively.The functional results were satisfactory.One 84-year-old patient with the implant intact died 2 years postoperatively from a brain hemorrhage. Conclusions Hip arthroplasty is an effective salvage procedure after the failed treatment of intertrochanteric fractures in elderly patient.Most patients have better pain relief and functional improvements in spite of technical difficulties than primary arthroplasty.In the meantime,attention should be paid to patients with poor bone quality,bone loss,or articular cartilage damage.

Objective To investigate the role of hybrid bone grafting using autograft and freezedried allograft bone in restoration of acetabular bone defect,as well as to evaluate the clinical results of this grafting technique combined with acetabular scaffold in dealing with massive acetabular deficiency.Methods Between April 1999 to December 2007,18 patients (19 hips) underwent acetabular revision by using a mixture of autograft and allogenic freeze-dried cancellous bone particles plus acetabular scaffold.There were 8males and 10 females,aged from 33 to 76 years (average,64.7 years).The acetabular defects were caused by aseptic loosening of primary total hip arthroplasty in 17 patients and osteoarthritis secondary to osteotomy in 1 case of acetabular dysplasia.There were 5 cases of Paprosky Ⅱ B defect,2 Paprosky Ⅱ C defect,6 Paprosky ⅢA defect and 6 Paprosky ⅢB defect.Results All patients were followed up for 3.6 to 12.3 years (average,6.5 years).Harris hip score improved from preoperative 38.7±9.6 to 87.6±7.8 at final follow-up.According to X-rays,bone incorporation evidenced by trabecular bridging of the host-donor interface was found at 3to 6 months postoperatively,and effective bone incorporation was achieved in all cases one year postoperatively.Polyethylene wear occurred in one case.Acetabular component loosening was not found at final follow up.Conclusion Impacted bone grafting using a mixture of autograft and freeze-dried allograft bone can efficiently restore acetabular bone defect.Adding autograft bone to freeze-dried allograft bone is a highly effective way of achieving graft incorporation.Hybrid bone grafting technique with acetabulum scaffold is an attractive option for the treatment of extensive acetabular deficiency.

Objective To summarize the perioperative characters of femoral neck fractures in patients aged at over 80 years by analyzing the surgical treatment procedures. Methods A retrospective study was done on data of patients with femoral neck fractures treated surgically from June 2000 and June 2008. There were 25 males and 36 females, at average age of 83.4 years (80-94 years). Of all, there were 53 patients with fresh fractures including six with type Garden Ⅰ or Ⅱ fractures and 47 with type Garden Ⅲ or Ⅳ fractures, eight with old fractures ( all type Garden Ⅳ). Fifty-one patients (84%) were accompanied with preexisted internal medical or neurological diseases. Six patients with type Garden Ⅰ or Ⅱ fractures were treated with cannulated screw fixation (CSF). Among 55 patients with type Garden Ⅲ or Ⅳ fractures inclu-ding 47 fresh fractures and 8 old ones, 53 patients were treated by hip hemiarthroplasty (HHA) but the other two by cemented total hip arthroplasty (THA) because of preexisting hip osteoarthritis. Results The average operation duration and blood loss were 51 minutes and 50 ml in CSF group, 81 minutes and 180 ml in HHA group, 105 minutes and 350 ml in THA group. Fifteen patients (25%) had postoperative com-plications, mostly hypotension, cardiac insufficiency and atrial fibrillation, accounting for 12%. Postoperative hemoglobin was decreased by 11.9%, 17.1% and 18. 1% on average respectively in CSF group, HHA group and THA group, and postoperative albumin decreased by 10.8%, 18. 1% and 20.2% on average respectively in CSF group, HHA group and THA group. There were 17 patients (28%) with hemoglobin below 100 g/L and four (7%) with albumin below 30 g/L after operation. Conclusions The patients aged ≥80 years with femoral neck fractures are usually accompanied with preexisted internal medical or neurological diseases and have high risk in operation. Adequate preoperative preparation and active prevention and treatment of perioperative complications are important for successful operation and good postoperative results.

[Objective]To analyze the failure mechanisms in patients undergoing revision surgery in different time after index total hip arthroplasty(THA).[Method]The clinical records and radiographs of 78 revision hip surgeries between June 1995 and June 2005 loere reviewed.Forty-two cases were total hip arthroplasty and 36 were hemiarthroplasty.Thirty-six patients had revision surgery within 5 years and 42 more than 5 years.[Result]The causes of early revision THA included infection(16 cases),aseptic loosening,acetabular erosion,and mechanical failure.In the late revision THA,aseptic loosening was the most common reason,and the next common reason were acetabular wear and osteolysis around a well-fixed implant.[Conclusion]Infection is a common reason for the early revision.Aseptic loosening is the major cause for the late revision total hip arthroplasty.

[Objective] To investigate the radiographic changes of patella after total knee arthroplasty(TKA)with non-resurfaced patellar.[Methods]Fifty-one patients(64 knees)underwent TKA with patellar non-resurfaced.Average age was 68.5 years(range,57~78 years).Average follow-up was 4.8 years(range,2.5~8 years).The radiographic changes of patella,patellar tilt,and patellar lateral shift were evaluated.The functional results of patellofemoral joint were analyzed.[Results]The patellar tilt and lateral shift were improved obviously after surgery.Most patella tracking lied in the middle and there were no obvious degeneration with the time passing.Osteophytes formation and deterioration of patellar tracking were the most common abnormal radiographic changes.There were no obvious relationship between symptoms of patellofemoral joint and patellar degeneration.[Conclusion]Patellar tracking can be improved immediately after non-resurfaced total knee arthroplasty in osteoarthritis patients.There will not be obvious patellar degenerative changes with time passing.