The kinematics modeling based on Spinor theory for CT-guided hybrid robot

This paper focused on a simplified method for solving the hybrid robot kinematics in CT-guided （computerized tomography, CT） surgery. By position constraint introduced, the hybrid robot can be transformed as a redundant serial 7-DOF robot. The forward displacement calculation was developed based on the product-of-exponential formula （POE）. Because of the kinematics complexity of the hybrid and redundant robot, the combination technique of Ulrich two-step iteration method and paul variables detachment method （UTI-PVD） was introduced to fulfill the inverse kinematics of redundant robot, the novelty of which lay in the flexibility of various robots structures and in high calculation efficiency for realtime control. The process of solving the inverse displacement was analyzed. The UTI-PVD method can be applicable to kinematics of many robots, especially for redundant robots with more than 6DOF. The kinematics simulation was provided, and robot dexterity analysis was presented. The results indicated that the hybrid robot could implement the minimally invasive CT-guided surgery.

Percutaneous CT-Guided Drainage of Gastric Leaks Post-Sleeve Gastrectomy

Objectives: The aim of this study was to assess the safety and efficacy of percutaneous CT-guided drainage of gastric leaks post sleeve gastrectomy. Methods: For this single-center retrospective study, we reviewed the clinical data of 78 patients (44 men and 34 women with an average age of 34.6 ±10.5 years and a body mass index (BMI) of 45 kg/m2 ±3.2) that underwent percutaneous CT-guided drainage of gastric leaks due to sleeve gastrectomy from September 2011 to September 2018. The outcome measurements were technical and clinical success, complications, and the need for revisional surgery. Results: The technical success rate of drain insertion was 97.5% (76/78 patients). All of the patients (76/76 patients) exhibited early clinical and laboratory improvement, and no emergency surgery was required. However, six patients underwent revisional surgery after 3 - 5 months for non-healing gastric leaks/fistulas. One patient had a major complication of active bleeding due to arterial injury;this was managed by transcatheter coil embolization. All patients underwent endoluminal stent placement and received antimicrobial therapy and nutritional support. Conclusion: Percutaneous CT-guided drainage of gastric leaks after sleeve gastrectomy is a safe, effective, and minimally invasive alternative to surgery. This technique is in line with other conservative measures (endoluminal stent placement, antimicrobial therapy, and nutritional support), which heal most gastric leaks due to sleeve gastrectomy and prevent the need for revisional surgery.

Contrast-Enhanced CT-Guided Core Biopsy of Retroperitoneal Masses

Objective: To evaluate the efficacy, feasibility and safety of contrast-enhanced CT-guided core biopsy of retroperitoneal masses. Materials and Methods: Contrast-enhanced CT-guided biopsy of retroperitoneal masses was performed in 26 patients. Histopathological diagnosis was obtained and accuracy was calculated. Two blinded radiologists determined feasibility of biopsy procedures on routine CT-guidance, and compared accessibility of target lesions using contrast-enhanced and non-contrast-enhanced CT. Results: Satisfactory samples were obtained in all 26 patients and pathological diagnosis was made in 24. Accuracy was 95.5%. Routine CT-guided biopsy punctures were not satisfaction in 4/26 patients, and contrast-enhanced CT scans rendered the target lesions more accessible in 16 patients. Conclusion: Contrast-enhanced CT-guided biopsy increases the feasibility of biopsy of retroperitoneal masses.

Effectiveness and Therapeutic Impact of CT-Guided Percutaneous Drainage for Deep Neck Abscesses

Objective: The purpose of this study is to evaluate the effectiveness and safety of CT-guided percutaneous drainage (CPD) in the management of deep neck abscesses. Factors associated with successful treatment in patients with DNA will be identified. Methods: We retrospectively studied 29 patients who presented to the department of otolaryngology with deep neck abscesses between April 2011 and April 2015. These 29 patients were managed with CPD after antibiotic therapy or needle aspiration failed. Data on patient demographics, location of infection, existing comorbidity, duration of hospitalization, treatment received, and complications were reviewed. Results: The average age of 29 patients, including 18 men and 11 women, was 56 years old. Abscess was found in parapharyngeal space (n = 16), submandibular space (n = 7), retropharyngeal space (n = 5) and pretracheal space (n = 1). The maximum transverse diameter of abscess ranged from 4.8 cm to 8.0 cm (mean 6.03 cm). Positive cultures were found in 24 cases and the most common pathogen found was Streptococcus viridans. Average hospital stay was 6.7 days. Deep neck abscesses were completely removed without residual in all patients. No one had complications and no one died during and after CPD. Conclusion: CPD is a safe and highly effective procedure for treating patients with deep neck abscesses who do not respond to antibiotics therapy. This technique can also provide reliable evidence on pathogens responsible for deep neck abscesses and help otolaryngologists choose effective treatment to achieve better clinical success rate. We recommend that most deep neck abscesses should be managed initially by CPD before resorting to open surgery.

Minioptical Navigation System for CT-Guided Percutaneous Liver Procedures

Purpose: To evaluate a new miniature optical navigation system for CT-guided liver interventions. Material and Methods: A two-center, prospective study was performed with four interventional radiologists. A total of 20 patients had CT-guided liver biopsy or ablation interventions utilizing the CT-Guide? navigation system (ActiViews Inc., Wakefield, MA) between July 2011 and December 2011. The navigation system consists of a self-adhesive patientsticker printed with coincident colored and radio-opaque reference markers, a miniature disposable video camera that clips on and off an interventional instrument, and software loaded on a computer to display the navigation information. The primary end point was the frequency of a satisfactory instrument position for the intended intervention. Results: The cohort consisted of 13 males and 7 females with an average age of 63.1 years (range of 38 to 80). Most of the patients, 70%, underwent CT-guided liver biopsy while the remainder had CT-guided ablation therapy. The average lesion size was 3.1 cm (range of 1.1 - 6.9 cm). All of the interventions, regardless of lesion size, met the primary end point of satisfactory instrument positioning. There were no device-related or unexpected adverse events recorded. Only one patient had a mild adverse event and it resolved without intervention. Conclusions: This study demonstrated the safety and effectiveness of the CT-Guide? navigation system for CT-guided liver interventions, for both biopsies and ablations. The targeting success rate for a satisfactory intervention was 100% with the system.

Computed tomography-guided transpulmonary radiofrequency ablation for hepatocellular carcinoma located in hepatic dome

AIM： To determine the feasibility of performing computed tomography （CT）-guided transpulmonary radiofrequency ablation （RFA） for hepatocellular carcinoma （HCC） located in the hepatic dome. METHODS： A total of seven patients with HCC comprising seven nodules located in the hepatic dome were treated from April 2004 to December 2004. CTguided transpulmonary RFA was performed using a cool-tip type electrode （Radionics Company） based on a standardized energy protocol. All tumors located in the hepatic dome were not detectable by the usual ultrasound （US） methods. The lesion diameters ranged from 15 to 27 mm. RESULTS： RFA was technically feasible in all the patients. The puncture procedure was performed twice or less and the total average performance time was 40.6 min. Local tumor control was achieved in all the patients. The necrosis diameter ranged from 25 to 35 mm. The mean follow-up period was 9.6 （7-14 mo） mo. There was no local recurrenceat the follow-up points. Pneumothorax requiring pleural drainage was the main complication, which was observed in two of the seven patients （28.6%）. However, it improved with chest drainage tube, and the tube could be removed within 2-3 d. No other major complications were observed.CONCLUSION： CT-guided puncture is useful for the treatment of tumors located in the hepatic dome which are hardly detectable by US, even though pneumothorax sometimes may occur as a complication. In the cases with adhesion in the pleura for which artificial pleural effusion methods are not appropriate, CT-guided RFA is thus considered to be an alternative treatment for HCC located in the hepatic dome.

Precise localization of small pulmonary nodules using Pre-VATS with Xper-CT in combination with real-time fluoroscopy-guided coil:report of 15 patients

Purpose: This study aimed to evaluate the value of precise localization of nodules using pre-video-assisted thoracic surgery(VATS) Xper–CT in combination with real-time fluoroscopy-guided coil in the resection of pulmonary nodules using VATS. Materials and Methods: Precise localization of nodules using Xper-CT in combination with real-time fluoroscopy-guided coil and wedge resection using VATS were conducted on 15 patients with 17 small pulmonary nodules(diameter 0.5–1.5 cm) from April 2015 to January 2016. The value of localization was evaluated in terms of procedure time, type of coils, associated complications of localization, and VATS success rate. Results: The success rate of coil localization was found to be 100% in the primary stage(as shown by the CT scan), and the average procedure time was 30–45 min(35.6 ± 3.05 min). No deaths or major complications occurred. Minor complications included five incidents of pneumothorax(the morbidity was 29.4%, 5/17; no patient required chest tube drainage). The dislocation of coil was found in one patient. The results of pathological examination of 17 small pulmonary nodules revealed 11 primary lung cancers, 1 mesenchymal tumor, 3 nonspecific chronic inflammations, 1 hamartoma, and 1 tuberculosis. Two patients with primary lung cancer underwent lobectomy with mediastinal lymph node dissection. Conclusion: The preoperative precise localization of small pulmonary nodules using Xper-CT-guided coil is an effective and safe technique. It helps in the resection of nodules using VATS. It increases the rate of lung wedge resection with few complications and allows for proper diagnosis with a low thoracotomy conversion rate.

Pancreatic tuberculosis in a human immunodeficiency virus positive patient:A case report

Despite the increased incidence of tuberculosis related to human immunodeficiency virus (HIV) in recent decades, pancreatic tuberculosis has rarely been described. We report a case of pancreatic tuberculosis in a 39-year- old African man who presented with progressive dysphagia, vomiting, weight loss and productive cough, accompanied by localized epigastric pain and one episode of melena. HIV-1 testing was positive and lymphocyte subset profile showed CD4 count of 9/mm3. Abdominal computed tomography (CT) scan with contrast revealed a cystic mass in the body of the pancreas, significant portal and retroperitoneal cystic adenopathy, and multiple cystic lesions in the spleen and liver. CT guided cyst aspiration and node biopsy detected Mycobacterium tuberculosis. The patient responded well on antituberculosis and antiretroviral therapy. Tuberculosis rarely involves the pancreas, probably due to the presence of pancreatic enzymes which interfere with the seeding of Mycobacterium tuberculosis. Pancreatic tuberculosis is considered to be the result of dissemination of the infection from nearby lymphatic nodes. Endoscopic ultrasound or CT guided fine needle aspiration for cytology is the recommended diagnostic technique. Although the prognosis is good with anti-tuberculosis treatment, it could be fatal without correct diagnosis and treatment. The clinician’s high index of suspicion of pancreatic tuberculosis and application of FNAB to obtain pathological evidence are extremely important to a correct diagnosis, especially in young HIV positive patients.

Diagnostic efficiency and complication rate of CT-guided lung biopsy： a single center experience of the procedures conducted over a 10-year period

Background Computed tomography （CT）-guided transthoracic lung biopsy is a well-established technique for the diagnosis of pulmonary lesions. The objective of this study was to evaluate the diagnostic efficiency and complication rate of CT-guided lung biopsy in a Chinese population. Methods CT-guided cutting needle lung biopsies were performed in our institution on 1014 patients between January 2000 and October 2010. A chest radiograph was taken after the biopsy. Data about basic patient information, final diagnosis, and complications secondary to biopsy procedure （pneumothorax and bleeding） were extracted. Results The diagnostic efficiency of CT-guided lung biopsy was 94.8%; only 53 patients did not get a final diagnosis from lung biopsy. Final diagnoses found 639 malignant lesions （63.0%） and 322 benign lesions （31.8%）. Pneumothorax occurred in 131 patients and 15 required insertion of an intercostal drain. Small hemoptysis occurred in 41 patients and mild parenchymal hemorrhage occurred in 16 patients. The overall complication rate was 18.5%. Conclusions CT-guided cutting needle biopsy of pulmonary lesions is a relatively safe technique with a high diagnostic accuracy. It can be safely performed in clinical trials.

RISK FACTORS OF CT-GUIDED PERCUTANEOUS LUNG BIOPSY COMPLICATIONS

Objective To evaluate the complication rate of CT-guided percutaneous lung biopsy and determine the risk factors for complications. MethodsA retrospective investigation of CT-guided percutaneous lung biopsy carried out between 2002 and 2009 was performed. The risk factors for complications were determined by multivariate analysis of variables related to patient demographics, lung lesions, and biopsy procedures. ResultsA total of 281 biopsy procedures were enrolled. The total complication rate was 55.9% with pneumothorax 32.4% (91/281) and bleeding 34.5% (97/281). The risk factors affecting pneumothorax rate were lesion location, lesion depth, and time of pleural pierce; and the risk factors affecting bleeding complications were lesion depth, lesion size, and age. Predictive models for pneumothorax and bleeding were established by logistic regression. The pneumothorax model had a sensitivity of 80.0% with a specificity of 62.4%,and the bleeding model had a sensitivity of 67.4% with a specificity of 88.8%. ConclusionLesion location, lesion depth, and number of pleural passes were independent risk factors for pneumothorax. Lesion size, lesion depth, and age were independent risk factor for bleeding. The predictive models for pneumothorax and bleeding will helpfully reduce the complication of CT-guided lung biopsy.

CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma

Background This study evaluated the feasibility, efficacy and safety of CT-guided percutaneous radiofrequency ablation in patients with spinal osteoid osteoma. Methods Two patients suffered spinal osteoid osteoma were treated with CT-guided percutaneous radiofrequency ablation under local anesthesia. Lesions located in sacral vertebrae and cervical vertebrae, which were adjacent to nerve root and spinal canal respectively. Tumors were treated under 90℃ radiofrequency temperature lasting 4 minutes by an electrode placement. Visual analog scale was used to evaluate the pain improvement. Results No complications were observed pre- and post-operation. Patients recovered to normal activities immediately and achieved complete pain relief in 24 hours. No symptoms were recurrent in 5 months and 4 months follow up. Mild scoliosis has been recovered in case 2. Conclusions CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma is safe, effective and has more clinical benefits. The long-term outcome needs further observation.