Robot-Assisted Needle Insertion for CT-Guided Puncture: Experimental Study with a Phantom and Animals

PURPOSE

This study aimed to evaluate the accuracy and safety of robotic CT-guided needle insertion in phantom and animal experiments.

MATERIALS AND METHODS

A robotic system was developed for CT-guided needle insertion. For the phantom experiment, a specially made phantom containing multiple spherical was used. 15 robotic and manual insertions were conducted, and the accuracy, time, number of needle insertions, and radiation dose were compared between the robotic and manual insertion using Student's t-test. For the animal experiment, 20 robotic needle insertions were attempted toward simulated pulmonary nodules in the swine lung. The accuracy and safety of robotic CT-guided needle insertions were evaluated.

RESULTS

In the phantom experiment, the mean accuracies of manual and robotic insertion were 1.8 ± 0.3 mm and 1.9 ± 0.2 mm. The accuracy of robotic needle insertion had no significant difference with manual needle insertion, but the number of needle insertions and radiation dose of the robotic needle placement significantly decreased compared to manual needle placement. In the animal experiment, the mean accuracy of the robotic needle insertion was 3.8 ± 1.3 mm. The time for the whole needle insertion was 14.4 ± 4.8 min. The whole robotic needle insertions were safe and only one mild pneumothorax occurred.

CONCLUSION

CT-guided robotic needle insertion showed accuracy comparable to manual needle insertion, but the number of needle insertions, confirmatory scans, and radiation exposure had been reduced significantly. In future, we will further apply the robotic system to clinical experiments.

Accessing Intraabdominal Abscess for Percutaneous Drainage Using a Trocar Only Technique to Maneuver Intervening Bowel

Conventional approaches to the drainage of abscess surrounded by bowel contraindicate percutaneous drainage and often involve more invasive laparotomy. We attempt to demonstrate the use of an image-guided blunt trocar to navigate obstructive bowel and access abdominal abscess. This report presents the use of a blunt trocar to safely maneuver obstructive bowel and perform successful percutaneous drainage of intraabdominal abscess in two separate cases: one presenting a left lower quadrant diverticular abscess and the other presenting an abscess in the right lower quadrant. Thus, traversing obstructive bowel using a blunt trocar under computed tomography-guidance allows for percutaneous drainage of an intraabdominal abscess, and provides a safer and more effective alternative to more invasive procedures.

High presacral collection approached through the perineal route: A novel computed tomography-guided technique

For a definitive diagnosis of abdomino-pelvic lesions, percutaneous aspiration or biopsy is often necessary; however, finding a safe 'window' for access is challenging. This case report discusses a novel method to approach a deep pelvic collection and also briefly reviews the various approaches to access such lesions. A sample was obtained from a non-resolving presacral collection using a CT-guided percutaneous, trans-perineal approach with repeated sessions of hydro-dissection. Successful aspiration and analysis revealed multi-drug resistant tuberculosis, thus guiding appropriate management.

ACR Appropriateness Criteria® Radiologic Management of Infected Fluid Collections

Infected fluid collections are common and occur in a variety of clinical scenarios throughout the body. Minimally invasive image-guided management strategies for infected fluid collections are often preferred over more invasive options, given their low rate of complications and high rates of success. However, specific clinical scenarios, anatomic considerations, and prior or ongoing treatments must be considered when determining the optimal management strategy. As such, several common scenarios relating to infected fluid collections were developed using evidence-based guidelines for management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

A New CT-Guided Modified Trocar Technique for Drainage of Difficult Locations Abscesses

PURPOSE

Computed tomography (CT) is commonly used to guide drainage of deep-seated abdominal fluid collections. However, in some cases, these collections seem to be inaccessible due to surrounding organs or their being in difficult locations. The aim of this study is to describe a modified Trocar technique to drain collections in difficult locations, especially those in the subphrenic space, without passing through intervening organs.

MATERIALS AND METHODS

This retrospective case series study describes seven inpatients who underwent CT-guided drainage using a modified Trocar technique for abscesses that are difficult to access percutaneously. All patients provided written informed consent prior to the procedure. After placement of a 12-14F catheter inside the peritoneum, the Trocar stylet was removed so that the tip of the catheter became blunt and flexible to avoid injury to organs and structures in the catheter route, and the catheter was slowly advanced towards the collection using CT guidance and tactile sensation. After reaching the target, the stylet was reintroduced to enter the abscess wall.

RESULTS

All procedures were performed using an anterior abdominal wall access with adequate catheter positioning and resulted in clinical status improvement in the days after the drainage. No complications related to the procedure were identified in any of the patients.

CONCLUSIONS

The modified Trocar technique for percutaneous CT-guided drainage of abdominal abscesses may be feasible for lesions that are difficult to access with conventional methods.

Kidney, Ureter, and Bladder Biopsy

Percutaneous urologic biopsy is a safe and effective technique and can comprise a significant proportion of the daily workload of the interventional radiologist. This article discusses the indications and rationale for the performance of renal, ureter, and bladder biopsy as well as the approach to performing such biopsies, pitfalls, and potential complications.

Percutaneous biopsy in the abdomen and pelvis: a step-by-step approach

Percutaneous abdominal biopsies provide referring physicians with valuable diagnostic and prognostic information that guides patient care. All biopsy procedures follow a similar process that begins with the preprocedure evaluation of the patient and ends with the postprocedure management of the patient. In this review, a step-by-step approach to both routine and challenging abdominal biopsies is covered with an emphasis on the differences in biopsy devices and imaging guidance modalities. Adjunctive techniques that may facilitate accessing a lesion in a difficult location or reduce procedure risk are described. An understanding of these concepts will help maintain the favorable safety profile and high diagnostic yield associated with percutaneous biopsies.

Difficult biopsy and drainage: just say yes

Abdominal radiologists are often asked to perform difficult percutaneous chest, abdomen, and pelvis biopsies and drainages with imaging guidance. Many of these procedures involve small target lesions far from the skin surface, in close proximity to critical structures. Organ location is changeable due to respiration, peristalsis, and pulsation, further complicating the planning process. High-level three-dimensional spatial awareness is critical to mastery of complex image-guided procedures. A comprehensive grasp of anatomy and expected changes can be exploited in certain cases to target lesions within a solid organ or to avoid injury to sensitive structures during biopsy, drain placement, or thermal ablation. In this article, we will use illustrative cases to explore the use of anatomic knowledge and the ability to synthesize this three-dimensional data dynamically during planning and execution of difficult CT- and ultrasound-guided procedures. We will discuss unusual biopsy requests-such as bowel biopsies-and the benefits of using ultrasound guidance for certain procedures in the chest. Additionally, we will describe multiple special techniques, including out of standard plane angulation and endocavitary techniques, in order to maximize chances of success.

Intracavitary contrast-enhanced ultrasound in abscess drainage--feasibility and clinical value

OBJECTIVE

To evaluate the usefulness of intracavitary-applied contrast-enhanced ultrasound (ICCEUS) with BR1 in ultrasound-guided puncture and drainage of abdominal and pelvic abscesses.

MATERIAL AND METHODS

A total of 71 consecutive patients received ICCEUS after placement of a drainage catheter or a needle in abdominal or pelvic abscesses. Portions of 0.1 ml of BR1 and 20 ml of saline were injected through the drainage catheter or needle. Ultrasound recordings were evaluated to answer the following questions: correct placement of the catheter by showing enhancement in the cavity and the drain - ICCEUS findings suggesting incomplete enhancement in all abscess cavities - enhancement in non-abscess structures.

RESULTS

About 52% of patients had liver, 14% of patients had intraperitoneal, 11% had subphrenic, 14% had retroperitoneal, 6% had splenic, and 4% had pelvic abscesses. The majority of the patients received drain placement with 10-F using trocar technique. Enhancement in the drain or needle was seen in all patients. In 2% of patients, during the initial approach, a dislodgment of the catheter from the abscess cavity was diagnosed. Due to non-enhancing abscess compartments, in 36% of the patients more than one drainage treatment was necessary at the time of the first approach. In 14% of the patients communication with surrounding structures was diagnosed. Additional treatment resulted in 4% of cases.

CONCLUSION

ICCEUS was helpful in all patients to confirm correct placement of drain or puncture needle. In 40% of patients, as a consequence of ICCEUS, additional therapy was scheduled, either additional drainage or abscess puncture, endoscopic retrograde drainage of the biliary or pancreatic duct or thoracic intervention.

The role of CT-guided percutaneous drainage of loculated air collections: an institutional experience

OBJECTIVE

The purpose of this study is to describe our experience with the role of CT-guided percutaneous drainage of loculated intra-abdominal collections consisting entirely of gas.

MATERIALS AND METHODS

An IRB-approved retrospective study analyzing patients with air-only intra-abdominal collections over an 8-year period was undertaken. Seven patients referred for percutaneous drainage were included. Size of collections, subsequent development of fluid, and microbiological yield were determined. Clinical outcome was also analyzed.

RESULTS

Out of 2835 patients referred for percutaneous drainage between 2004 and 2012, seven patients (5M, 2F; average age 63, range 54-85) met criteria for inclusion with CT showing air-only collections. Percutaneous drain placement (five 8 Fr, one 10 Fr, and one 12 Fr) using Seldinger technique was performed. Four patients (57%) had recently undergone surgery (2 Whipple, 1 colectomy, 1 hepatic resection) while two (29%) had a remote surgery (1 abdominoperineal resection, 1 sigmoidectomy). Despite the lack of detectable fluid on the original CT, 6 patients (86%) had air and fluid aspirated at drainage, 5 (83%) of the aspirates developed positive microbacterial cultures. Four patients (57%) presented with fever at the time of the initial scan, all of whom had positive cultures from aspirated fluid. Four patients (57%) had leukocytosis, all of whom had positive cultures from aspirated fluid.

CONCLUSIONS

Although relatively rare in occurrence, patients with air-only intra-abdominal collections with signs of infection should be considered for percutaneous management similar to that of conventional infected fluid collections. Although fluid is not visible on CT, these collections can produce fluid that contains organisms.

Hydrodissection-assisted image-guided percutaneous biopsy of abdominal and pelvic lesions: experience with seven patients

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of retroperitoneal organ displacement for image-guided percutaneous biopsy.

CONCLUSION

Organ displacement using 0.9% saline or 5% dextrose in water (D5W) can create safe access routes for targeted abdominal and pelvic biopsies.

Virtually no thoracic lesion inaccessible: a pictorial case review

Access route considerations in percutaneous intrathoracic biopsy or ablation offers its own unique set of challenges, with special consideration toward reducing the rate of pneumothorax. This review highlights several novel and atypical methods to improve access to intrathoracic lesions through a series of representative cases. These methods include patient positioning, curved needles, hydrodissection, induced/artificial pneumothorax, and use of specialized equipment functions. No intrathoracic lesion should be considered "inaccessible" either for biopsy or treatment by percutaneous approaches without consideration of performing these adjunctive techniques.

Approaches to the difficult drainage and biopsy

Percutaneous abscess drainage and percutaneous biopsy are effective and widely used techniques in the diagnosis and treatment of patients with abdominal or pelvic abscesses and lesions. Some abscesses and lesions can initially appear unsuitable for percutaneous access for a variety of reasons. This article reviews the circumstances in which collections or lesions may appear undrainable or inaccessible to percutaneous biopsy, and it describes techniques for overcoming these circumstances.

CT-guided celiac plexus neurolysis: a review of anatomy, indications, technique, and tips for successful treatment

The celiac plexus is the largest visceral plexus and is located deep in the retroperitoneum, over the anterolateral surface of the aorta and around the origin of the celiac trunk. It serves as a relay center for nociceptive impulses that originate from the upper abdominal viscera, from the stomach to the proximal transverse colon. Celiac plexus neurolysis, with agents such as ethanol, is an effective means of diminishing pain that arises from these structures. Percutaneous imaging-guided celiac plexus neurolysis has been established as an invaluable therapeutic option in the management of intractable abdominal pain in patients with upper abdominal malignancy. The use of multidetector computed tomography (CT) for imaging guidance has superseded other modalities and allows direct visualization of the spread of the neurolytic agent in the antecrural space. Accurate depiction of the retroperitoneal anatomy and the position of the needle tip helps avoid crucial anatomic structures such as the pancreas, aorta, celiac artery, and superior mesenteric artery. Proper patient education, meticulous preprocedure planning, use of optimal multidetector CT techniques, adjunctive CT maneuvers, and postprocedure care are integral to successful celiac plexus neurolysis. Celiac plexus neurolysis does not completely abolish pain; rather, it diminishes pain, helping to reduce opioid requirements and their related side effects and improving survival in patients with upper abdominal malignancy.