Three-dimensional ultrasound reconstruction of the pelvicaliceal system: an in-vitro study

Objectives  Three-dimensional (3D) reconstruction of the pelvicaliceal system (PCS) can be helpful for percutaneous renal procedures. 3D reconstruction of the PCS using ultrasound (US) has not been studied. We determined the feasibility and accuracy of 3DUS reconstruction of the PCS in an in vitro model. Methods  Ten pig kidneys were scanned in vitro using freehand 3DUS (Logiq 9, GE medical systems). Multi-planar reformatted (MPR) and volume rendered (VR) reconstructions of the PCS were processed on a workstation. Using resin casts of the PCS as the reference standard, MPR reconstructions were compared for maximal polar and antero-posterior (AP) PCS length, lower pole infundibular (LPInf) diameter and number of calices. VR movies were compared for number of calices. Three blinded reviewers matched VR movies to casts and given an “anatomical representation” score using a five-point scale. Results  There were no significant differences in maximal AP length, LPInf diameter or number of calices between MPR reconstructions and casts. Maximal polar length between MPR reconstructions and casts were different (t = 6.44, P = 0.0001). VR movie reconstructions underestimated the number of calices visualised (t = 3.23, P = 0.01). A total of 22 out of 30 (73%) 3D VR videos were accurately matched to their casts. The 3D VR median score for anatomical representation was 3 (fair representation). Conclusions  Three-dimensional ultrasound reconstruction of the porcine PCS is quantitatively comparable to corresponding casts of the PCS. 3D VR movies of the PCS were a fair representation of the PCS anatomy. 3DUS is a potential tool in the planning and execution of percutaneous renal procedures.     

MR/CT image fusion of the spine after spondylodesis: a feasibility study

The objective of this study is to evaluate feasibility, accuracy and time requirements of MR/CT image fusion of the lumbar spine after spondylodesis. Sagittal MR and CT images derived from standard imaging protocols (sagittal T2-weighted MR/sagittal reformatted multi-planar-reformation of the CT) of the lumbar spine with correct (n = 5) and incorrect (n = 5) implant position were fused by two readers (R1, R2) using OsiriX in two sessions placing one (session 1) or two (session 2) reference point(s) on the dorsal tip(s) of the cranial and caudal endplates from the second lumbar to the first sacral vertebra. R1 was an experienced musculoskeletal radiologist; R2 a spine surgeon, both had received a short training on the software tool. Fusion times and fusion accuracy, defined as the largest deviation between MR and CT in the median sagittal plane on the ventral tip of the cranial end plate of the most cranial vertebra visible on the CT, were measured in both sessions. Correct or incorrect implant position was evaluated upon the fused images for all patients by an experienced senior staff musculoskeletal radiologist. Mean fusion time (session 1/session 2; in seconds) was 100.4/95 (R1) and 104.2/119.8 (R2). Mean fusion deviation (session 1/session 2; in mm) was 1.24/2.20 (R1) and 0.79/1.62 (R2). The correct/incorrect implant position was identified correctly in all cases. In conclusion, MR/CT image fusion of the spine with metallic implants is feasible, fast, accurate and easy to implement in daily routine work.     

医学图像三维可视化系统在胰腺及壶腹周围肿瘤可切除性评估中的应用

Pancreatic cancer is malignant with a poor prognosis,and its incidence is rising worldwide in recent years.Multiple slices spiral computed tomography and computed angiography are the first choice for t...     

A pilot study to assess the feasibility,safety and cost of robotic assisted total hysterectomy and bilateral salpingo-oophorectomy

The aim of this study was to evaluate the safety, feasibility and cost-effectiveness of robotic assisted total hysterectomy and bilateral salpingo-oophorectomy (RATHBSO). Sixteen women underwent this new procedure for a variety of gynaecological indications. Outcome measures included operating time, estimated blood loss, length of hospital stay and cost. No intra-operative complications were recorded. Fifteen patients were discharged on day 1 following the procedure, and one patient stayed an extra day for pain relief. The cost of the procedure compared favourably with other surgical hysterectomy techniques. We conclude that RATHBSO is a feasible and safe surgical technique with all the advantages of minimal access surgery and equivalent cost.     

An evaluation of the feasibility, validity, and reliability of laparoscopic skills assessment in the operating room

OBJECTIVE: To assess the use of a synchronized video-based motion tracking device for objective, instant, and automated assessment of laparoscopic skill in the operating room. SUMMARY BACKGROUND DATA: The assessment of technical skills is fundamental to recognition of proficient surgical practice. It is necessary to demonstrate the validity, reliability, and feasibility of any tool to be applied for objective measurement of performance. METHODS: Nineteen subjects, divided into 13 experienced (performed >100 laparoscopic cholecystectomies) and 6 inexperienced (performed <10 LCs) surgeons completed LCs on 53 patients who all had a diagnosis of biliary colic. Each procedure was recorded with the ROVIMAS video-based motion tracking device to provide an objective measure of the surgeon's dexterity. Each video was also rated by 2 experienced observers on a previously validated operative assessment scale. RESULTS: There were significant differences for motion tracking parameters between the 2 groups of surgeons for the Calot triangle dissection part of procedure for time taken (P = 0.002), total path length (P = 0.026), and number of movements (P = 0.005). Both motion tracking and video-based assessment displayed intertest reliability, and there were good correlations between the 2 modes of assessment (r = 0.4 to 0.7, P < 0.01). CONCLUSIONS: An instant, objective, valid, and reliable mode of assessment of laparoscopic performance in the operating room has been defined. This may serve to reduce the time taken for technical skills assessment, and subsequently lead to accurate and efficient audit and credentialing of surgeons for independent practice.     

成骨蛋白-1在腰椎融合术中应用的实验研究

目的:探讨成骨蛋白-1(OP-1)在脊柱融合术中的作用。方法:选用12只成年猕猴接受腰椎融合术,实验组、对照组分别采用OP-1加自体骨、单纯自体骨植骨。术后当日和术后4、8、12、16、20周分别拍腰椎正位片,观察植骨生长的情况。术后12周和20周分批处死动物,取脊柱标本进行生物力学和组织学研究。结果:术后第12周X线检查发现,OP-1组中,3只猕猴获双侧牢固融合,2只单侧牢固融合,1只部分融合;对照组只有1只获单侧牢固融合。实验组的植骨融合效果明显优于对照组,而且融合时间也明显提前,但两组的扭转刚度无显著性差异(P>0.05)。组织形态学评估发现,实验组的总平均成骨值为0.87±0.10,对照组为0.45±0.20,两组的成骨值有显著性差异(P<0.01),实验组的成骨活性明显高于对照组。结论:在无脊柱内固定的条件下,OP-1对脊柱后外侧融合具有显著的促进作用,可提高融合效率,缩短融合时间。     

MRI图像融合技术在肛瘘评估中的初步应用

目的采用图像融合技术获得T2WI与T2WI-FS的融合图像,评估其在肛瘘及肛周结构显示中的优势。 方法2016年6月至2018年6月,前瞻性选择中山大学附属第一医院29例肛瘘患者进行肛管磁共振（MR）检查,采用图像融合技术获取T2WI与T2WI-FS的融合图像T2WI-Fusion,利用Fisher score算法计算瘘管及肛门括约肌的组织间分辨力Fisher值、脂肪与肛门括约肌间的Fisher值,评估融合图像中瘘管及肛周结构的显示情况。采用改进的双刺激连续质量量表（DSCQS）对T2WI-FS、T2WI、增强3D-VIBE和T2WI-Fusion序列图像进行主观图像质量评价。 结果29例患者均成功获得T2WI与T2WI-FS的融合图像T2WI-Fusion。T2WI-Fusion、T2WI瘘管与括约肌间Fisher均值分别为6.46、3.31,T2WI-Fusion图像对瘘管的显示优于T2WI序列图像（P<0.001）。T2WI-Fusion、T2WI-FS脂肪与括约肌间Fisher均值分别为10.61、2.45,T2WI-Fusion图像对括约肌的显示优于T2WI-FS序列图像（P<0.001）。T2WI-Fusion对瘘管与括约肌的图像质量评价总评分均高于T2WI-FS、T2WI、增强3D-VIBE序列（P<0.001）。 结论MRI图像融合技术同时具备T2WI及T2WI-FS的优势,无需增加扫描序列及扫描时间,且操作简单,花费时间短,显著提高病变及肛周解剖结构的对比度和图像质量。     

犬自体静脉与腹膜碎片镶嵌种植人工血管的研究

目的:探讨加速人工血管内皮化,提高人工血管移植后通畅率的途径.方法:犬自体静脉与腹膜碎片镶嵌种植人工血管,行股动脉移植.结果与结论:细胞镶嵌种植后的人工血管在短期内形成了管腔内皮化,提高了人工血管移植通畅率.光、电镜及免疫组化观察,证实了移植血管新生内膜的细胞组成.内膜厚度测定,种植组与对照组间差异显著(P<0.01 ),内皮化后抑制了内膜的增生.腹膜间皮细胞与内皮细胞在形态及功能上的相似性,使其同样具有很好的应用前景.镶嵌种植技术为一快速、简便的人工血管内皮化方法,具有较高的临床应用价值.     

An open-label, randomized, flexible-dose, crossover study to assess the comparative efficacy and safety of sildenafil citrate and apomorphine hydrochloride in men with erectile dysfunction

Two papers in this section deal with well‐known pharmacological agents used to treat male erectile dysfunction. In the first of these, authors from the UK compared the efficacy and safety of sildenafil and apomorphine in such patients. This open‐label crossover trial suggested that sildenafil was better than apomorphine, where the primary endpoint was the erectile function domain of the International Index of Erectile Function. The second paper is an update on the efficacy and safety of tadalafil. It describes the results of its use in a large number of men with erectile dysfunction, compared to placebo. Once again, the erectile function domain was one of the primary endpoints. Tadalafil was an effective and well tolerated treatment for this condition.

OBJECTIVE

To compare the efficacy and safety of sildenafil and apomorphine in the treatment of men with erectile dysfunction (ED).

PATIENTS AND METHODS

In all, 139 men with ED who were naïve to treatment were entered into an open‐label crossover trial with two treatment periods, each of 8 weeks, separated by a 2‐week washout period. Men were randomized to receive either sildenafil then apomorphine or apomorphine then sildenafil, and were allowed to titrate the dose on both drugs. The primary endpoint was the erectile function (EF) domain of the International Index of Erectile Function (IIEF), and other endpoints included diary data, the other domains of the IIEF, overall assessment questions and the Erectile Dysfunction Index of Treatment Satisfaction (EDITS) questionnaire.

RESULTS

The EF domain score after treatment was 25.2 for sildenafil and 15.9 for apomorphine. The treatment difference of the adjusted means was 9.3 points (95% confidence interval 7.6–11.1; P < 0.001). After sildenafil the successful intercourse rate was 75%, vs 35% for apomorphine (P < 0.001), and the EDITS scores were 82.5 for sildenafil and 46.8 for apomorphine (P < 0.001). Of the men, 96% expressed a preference for sildenafil as a treatment for their ED. The side‐effect profiles for both drugs were in keeping with published data.

CONCLUSION

By all measurable endpoints sildenafil was superior to apomorphine in this open‐label crossover study of men with ED who were naïve to therapy

     

A prospective study demonstrating the reliability and validity of two procedure-specific evaluation tools to assess operative competence in laparoscopic colorectal surgery

Background

Laparoscopic colorectal surgery is considered an advanced minimally invasive procedure with a long, variable learning curve. Developing an evaluation tool is essential to ensure that individuals reach a certain level of competence prior to performing this procedure independently. To achieve standardization and wide implementation, an assessment tool must be reflective of practice across many institutions.

Study design

The purpose of this study is to validate two procedure-specific evaluation tools for laparoscopic colorectal surgery that were developed using innovative consensus methodology. Two procedure-specific rating scales for laparoscopic right and sigmoid colectomy were created using the Delphi method. Nine novice and nine expert laparoscopic sigmoid colectomy videos were prospectively collected, and nine novice and ten expert laparoscopic right colectomy videos were recorded. The experts rated the videos using the procedure-specific technical skills evaluation tool for either laparoscopic right colectomy or laparoscopic sigmoid colectomy.

Results

There were statistically significant differences between the expert and novice scores on the laparoscopic right colectomy evaluation tool: the median score of novices was 63.8% and the expert score was 73.1% (p?=?0.02). Similarly, there was a significant difference between the median novice score on the sigmoid tool (58.6%) compared with the median expert score (70.7%) (p?=?0.003). Cronbach’s alpha was 0.82 for the right colectomy evaluation tool and 0.79 for the sigmoid rating scale.

Conclusions

The procedure-specific evaluation tools for laparoscopic right and sigmoid colectomy demonstrate strong reliability and construct validity, and have the potential to be used for technical skills assessment and feedback.     

Reliability and validity of plain radiographs to assess angulation of small finger metacarpal neck fractures: human cadaveric study.

To quantify reliability and validity of plain radiographs for assessing the degree of small finger metacarpal neck fracture angulation, we created typical two-fragments fractures in 30 adult cadaveric specimens. Reliability and validity of different radiographic measurement methods were determined by the intraclass correlation coefficient (ICC) and the Bland and Altman graphical approach. Intraobserver and interobserver reliability was high with any radiographic measurement method. Mean ICCs values (95% confidence intervals) varied from 0.76 (0.56-0.88) to 1.00 (0.99-1.00). The graphical approach confirmed good agreement. Validity was substantial when the fracture angle was measured between the line along the longitudinal axis of the metacarpal shaft and the line from the center of the metacarpal head to the fracture site on lateral radiographs. Mean ICCs values varied from 0.70 (0.36-0.86) to 0.79 (0.5-0.90). The graphical analysis also indicated good agreement. In contrast, considerable lack of validity was observed when the angle was measured on oblique radiographs. Although the mean ICCs values varied from 0.68 (0.12-0.88) to 0.74 (0.05-0.90), suggesting substantial correlation, the graphical analysis provided evidence for poor validity. There was systematic bias with oblique radiographs consistently producing higher readings (up to 35 degrees ). In summary, reliability and validity are good only when the degree of small finger metacarpal neck fracture angulation is measured after drawing lines on lateral radiographs. Oblique radiograph measurements consistently produce higher readings.     

局部随意皮瓣修复颜面部皮肤软组织缺损的应用

目的 探讨采用局部随意皮瓣修复颜面部各种病变切除后及外伤致皮肤软组织缺损的临床效果.方法 2008年7月-2013年6月,应用局部随意皮瓣修复颜面各部位皮肤软组织缺损56例,根据缺损的部位、形状及大小,设计不同的局部随意皮瓣,转移修复颜面部皮肤软组织缺损创面.结果 术后皮瓣全部存活良好,所有创面均Ⅰ期修复,随访3～6个月,切口愈合良好,色素沉着及瘢痕增生不明显,外形效果满意.结论 应用局部随意皮瓣修复颜面部皮肤软组织缺损可获得得满意的外观和功能效果,值得临床推广.     

A study of the long-term precision of dual-energy X-ray absorptiometry bone densitometers and implications for the validity of the least-significant-change calculation

Introduction Short-term precision is often quoted and used as the most important performance parameter of a dual-energy X-ray absorptiometry (DXA) scanner; however, long-term precision has a more profound impact on patient monitoring. Long-term precision refers to the combination of in-vivo precision errors and long-term equipment stability. Methods To monitor long-term equipment stability, a phantom was designed with four inserts ranging in bone-mineral density from 0.5 to 3.3 g/cm². This phantom was used to monitor the equipment stability of four modern fan-beam densitometers, two each from Hologic and GE/Lunar, over a 4-year period. Manufacturer-recommended quality assurance (QA) procedures were performed, and the scanners stayed within manufacturer-specified tolerances throughout the study. Results and conclusion During the 4-year period, the Hologic scanners were observed to cause clinically insignificant BMD shifts (maximum of 0.34%), whereas the GE/Lunar scanners revealed BMD shifts that were clinically significant (1.5% and 2.1%). As a result, using least-significant-change (LSC) calculations based only on short-term in-vivo precision studies for monitoring patients is not valid for the two GE/Lunar densitometers due to the poorer long-term stability they exhibited.     

An in-vitro animal bone model study to predict spiral fracture strength of long bones in the young infant

IntroductionThe risk of fracture from a non-accidental injury is highest in the infant age group. A spiral fracture of the long bone can occur equally from accidental and non-accidental causes, meaning the clinical judgement of non-accidental injury in an infant is particularly challenging. This study aimed to assist in differentiating accidental, from non-accidental, injury in infants, by establishing whether correlation exists between geometry and torsional strength in the immature long bone.MethodsImmature porcine third and fourth metacarpals (n = 21) were imaged with a dual energy x-ray absorptiometry (DEXA) scanner to measure their linear bone mineral content (BMC_L), bone mineral density (BMD) and section modulus (Z). The specimens were then subjected to a torque of one degree per second until failure. The failure strength and the three DEXA measures were analyzed for a correlation.ResultsThe mean failure strength of 11 successful tests was 13.71Nm (+/-SD 2.42Nm), with correlation to BMC_L, BMD and Z described by r² = 0.81, 0.283 and 0.75 respectively.ConclusionThis study is a novel attempt at estimating torsional strength of long bones in a specific paediatric age group using a size-matched animal bone model. It found a strong correlation between bone and fracture strength parameters over the BMC_L range of 0.59–0.77 g/cm.     

Ability of navigated 3D ultrasound to delineate gliomas and metastases – comparison of image interpretations with histopathology

Summary Background. The objective of the study was to test the ability of a 3D ultrasound (US) based intraoperative imaging and navigation system to delineate gliomas and metastases in a clinical setting. The 3D US data is displayed as reformatted 2D image slices. The quality of the displayed 3D data is affected both by the resolution of the acquired data and the reformatting process. In order to investigate whether or not 3D US could be used for reliable guidance in tumour surgery, a study was initiated to compare interpretations of imaged biopsy sites with histopathology. The system also enabled concomitant comparison of navigated preoperative MR with histopathology. Method. Eighty-five biopsies were sampled between 2–7 mm from the tumour border visible in the ultrasound images. Biopsies were collected from 28 operations (7 low-grade astrocytomas, 8 anaplastic astrocytomas, 7 glioblastomas and 6 metastases). Corresponding cross-sections of preoperative MR T1, MR T2 and intraoperative US were concomitantly displayed, steered by the biopsy forceps equipped with a positioning sensor. The surgeons’ interpretation of the images at the electronically indicated biopsy sites were compared with the histopathology of the samples. Findings. The ultrasound findings were in agreement with histopathology in 74% (n = 31) for low-grade astrocytomas, 83% (n = 18) for anaplastic astrocytomas, 77% (n = 26) for glioblastomas and 100% (n = 10) for metastases. Excluding irradiated patients, the results for glioblastomas improved to 80% concurrence (n = 20). As expected tumour cells were found in biopsies outside the US visible tumour border, especially in low-grade gliomas. Navigated 3D US have a significantly better agreement with histopathology than navigated MR T1 for low-grade astrocytomas. Conclusion. Reformatted images from 3D US volumes give a good delineation of metastases and the solid part of gliomas before starting the resection. Navigated 3D US is at least as reliable as navigated 3D MR to delineate gliomas and metastases.     

颈前路单椎间减压植骨融合与加用钛板内固定的比较研究

目的通过生物力学研究和临床随访研究,探讨对无明显后凸畸形和节段不稳的单节段颈椎间盘突出症或颈椎病患者行前路单椎间减压植骨融合后是否有必要加用钛板内固定。方法采用16具新鲜尸体颈椎标本,测量单纯植骨组和加用钛板内固定组在2.0Nm纯力矩载荷下的运动范围;应用有限元力学分析计算出各时相两组的骨痂强度及与融合节段相邻部分的平均应力水平。临床随访同时期施行单纯植骨融合的27例与加用钛板内固定的18例患者,比较3年以上疗效;同时随访行单纯植骨融合的33例患者,评价10年以上疗效。结果尸体标本生物力学试验结果显示术后即刻加用钛板内固定组的稳定性高于单纯植骨融合组(P<0.05)。有限元力学分析显示:术后0.5年起单纯植骨融合组的骨痂强度和融合节段相邻的C5椎体平均应力水平与加用钛板内固定组基本相当;颈椎前部结构总体应力水平随植骨融合而增加,后部结构总体应力水平随植骨融合而减小。单纯植骨融合组与加用钛板内固定组术后3年以上随访疗效相当;单纯植骨融合术后10年以上随访总体疗效满意。结论对不伴明显后凸畸形和节段不稳的单节段颈椎间盘突出症或颈椎病,前路单椎间减压植骨融合与加用钛板内固定的疗效相当。     

组织工程神经修复大鼠坐骨神经缺损的研究

目的观察组织工程神经修复SD大鼠1．5cm长坐骨神经缺损的效果。方法用甘油处理10只SD大鼠2．0cm长坐骨神经，制备成同种异体脱细胞基质，备用。取SD乳鼠10只，分离坐骨神经，去神经外膜后，剪成小碎块，在DMEM中培养3周，扩增后的细胞鉴定、备用。3个月龄的SD雌性大鼠40只，单纯随机分成4个神经移植组（A、B、C、D），每组10只。A组：用扩增的雪旺细胞加同种异体脱细胞基质桥接，即组织工程化人工神经组。B组：用元雪旺细胞但具有内部支架结构的同种异体脱细胞基质桥接。C组：自体神经移植组。D组；空白对照组。术后12周，进行一般情况、小腿三头肌湿重、再生神经的组织学观察。结果完成对40只大鼠（每组10只）的实验评估。所有大鼠伤口瑚愈合，元死亡。A、B、C组大鼠足部元溃疡形成，D组7只足部有溃疡形成，所有组实验侧小腿三头肌较健侧萎缩，但以D组最明显。小腿三头肌湿重、神经电生理监测A组、C组差异无统计学意义（P〉O．05），A、C组与B、D组差异有统计学意义（P〈O．05），B组与D组差异有统计学意义（P〈0．05）。A组和C组的胫前肌中均能诱发出波幅明显的神经肌肉复合动作电位（CMAP），B组、D组中则仅录到波幅很低的CMAP。A组和C组再生轴突已通过移植段神经全长，远端肌肉轻度萎缩。B组部分通过移植段神经；D组不能通过移植段神经，6例形成神经瘤。结论组织工程人工神经可用来修复大鼠长段神经缺损。     

Regenerative repair of bone defects with osteoinductive hydroxyapatite fabricated to match the defect and implanted with combined use of computer-aided design, computer-aided manufacturing, and computer-assisted surgery systems: a feasibility study in a canine model

BackgroundCurrently, regenerative repair of large bone defects that result from bone tumor resection or severe trauma is a challenging issue because of the limited regenerative potential of bone and treatment modalities. The aim of this study was to achieve repair of large bone defects to the original three-dimensional (3D) anatomical state by combining computer-aided technologies and local delivery of bone morphogenetic protein (BMP) in a canine model.MethodsComputed tomography (CT) images of the pelvic bone of each dog were obtained, and an imaginary spherical malignant bone tumor of 15-mm diameter was placed in the left ilium of a canine on the 3D CT image. Resection of the whole tumor with a 10-mm margin of healthy bone was planned preoperatively by using computer-aided design (CAD) software. In addition, an image of the implant to be used to fill the resulting bone defect was constructed on the computer image. A porous hydroxyapatite (HA) implant identical to the imaged bone defect was made by shaving a tetragonal porous apatite block (40 × 20 × 10 mm) with a computer-aided manufacturing system operated by using the CT-image data of the bone defect obtained from the CAD system. To resect the iliac bone as planned preoperatively on the 3D CT image, computer-aided surgery was performed using the CT data. The defect was filled with the HA implant fabricated as described and coated with a putty carrier either with BMP-2 (BMP group, n = 6) or without BMP-2 (control group, n = 6).ResultsIn the BMP group, new bone formation was noted around each implant on CT images at 3 weeks after surgery and was remodeled to restore the original anatomy of the ilium on serial CT images. At 12 weeks, the implant was enclosed within new bone, and histological analysis revealed bone formation on and within the implant. Little bone formation was noted in the control group.ConclusionsThis new method may enable efficacious and precise regenerative repair of large bone defects without bone grafting.