Does lateral arm technique decrease the rate of clip migration in stereotactic and tomosynthesis-guided biopsies?

Background Mammography-guided vacuum-assisted biopsies (MGVAB) can be done with stereotaxis or digital breast tomosynthesis guidance. Both methods can be performed with a conventional (CBA) or a lateral arm biopsy approach (LABA). Marker clip migration is relatively frequent in MGVAB (up to 44%), which in cases requiring surgery carries a risk of positive margins and re-excision. We aimed to compare the rates of clip migration and hematoma formation between the CBA and LABA techniques of prone MGVAB. Our HIPAA compliant retrospective study included all consecutive prone MGVAB performed in a single institution over a 20-month period. The LABA approach was used with DBT guidance; CBA utilized DBT or stereotactic guidance. The tissue sampling techniques were otherwise identical. Results After exclusion, 389 biopsies on 356 patients were analyzed. LABA was done in 97 (25%), and CBA in 292 (75%) cases. There was no statistical difference in clip migration rate with either 1 cm or 2 cm distance cut-off [15% for CBA and 10% for LABA for 1 cm threshold (p = 0.31); 5.8% or CBA and 3.1% or LABA for 2 cm threshold (p = 0.43)]. There was no difference in the rate of hematoma formation (57.5% in CDB and 50.5% in LABA, p = 0.24). The rates of technical failure were similar for both techniques (1.7% for CBA and 3% for LABA) with a combined failure rate of 1%. Conclusions LABA and CBA had no statistical difference in clip migration or hematoma formation rates. Both techniques had similar success rates and may be helpful in different clinical situations.

Development of a miniaturized robotic guidance device for stereotactic neurosurgery

OBJECTIVE Consistently high accuracy and a straightforward use of stereotactic guidance systems are crucial for precise stereotactic targeting and a short procedural duration. Although robotic guidance systems are widely used, currently available systems do not fully meet the requirements for a stereotactic guidance system that combines the advantages of frameless surgery and robotic technology. The authors developed and optimized a small-scale yet highly accurate guidance system that can be seamlessly integrated into an existing operating room (OR) setup due to its design. The aim of this clinical study is to outline the development of this miniature robotic guidance system and present the authors’ clinical experience. METHODS After extensive preclinical testing of the robotic stereotactic guidance system, adaptations were implemented for robot fixation, software usability, navigation integration, and end-effector application. Development of the robotic system was then advanced in a clinical series of 150 patients between 2013 and 2019, including 111 needle biopsies, 13 catheter placements, and 26 stereoelectroencephalography (SEEG) electrode placements. During the clinical trial, constant modifications were implemented to meet the setup requirements, technical specifications, and workflow for each indication. For each application, specific setup, workflow, and median procedural accuracy were evaluated. RESULTS Application of the miniature robotic system was feasible in 149 of 150 cases. The setup in each procedure was successfully implemented without adding significant OR time. The workflow was seamlessly integrated into the preexisting procedure. In the course of the study, procedural accuracy was improved. For the biopsy procedure, the real target error (RTE) was reduced from a mean of 1.8 ± 1.03 mm to 1.6 ± 0.82 mm at entry (p = 0.05), and from 1.7 ± 1.12 mm to 1.6 ± 0.72 mm at target (p = 0.04). For the SEEG procedures, the RTE was reduced from a mean of 1.43 ± 0.78 mm in the first half of the procedures to 1.12 ± 0.52 mm (p = 0.002) at entry in the second half, and from 1.82 ± 1.13 mm to 1.57 ± 0.98 mm (p = 0.069) at target, respectively. No healing complications or infections were observed in any case. CONCLUSIONS The miniature robotic guidance device was able to prove its versatility and seamless integration into preexisting workflow by successful application in 149 stereotactic procedures. According to these data, the robot could significantly improve accuracy without adding time expenditure.

Using a Robotic-Assisted Approach for Stereotactic Laser Ablation Corpus Callosotomy: A Technical Report

<b><i>Background:</i></b> Corpus callosotomy for medically intractable epilepsy is an effective ablative procedure traditionally achieved using either standard open craniotomy or with less-invasive approaches. Advances in robotic-assisted stereotactic guidance for neurosurgery can be applied for LITT for corpus callosotomy. <b><i>Clinical Presentations:</i></b> Two patients were included in this study. One was a 25-year-old female patient with extensive bi-hemispheric malformations of cortical development and medically refractory epilepsy, and the other was an 18-year-old male with medically refractory epilepsy and atonic seizures, who underwent a complete corpus callosotomy using robotic-assisted stereotactic guidance for LITT. <b><i>Results:</i></b> Both patients underwent successful intended corpus callosotomy with volumetric analysis demonstrating a length disconnection of 74% and a volume disconnection of 55% for patient 1 and a length disconnection of 83% and a volume disconnection of 33% for patient 2. Postoperatively, both patients had clinical reductions in seizure. <b><i>Conclusion:</i></b> Our experience demonstrates that robotic guidance systems can safely and effectively be adapted for minimally invasive LITT corpus callosotomy.

Primary efficacy of percutaneous microwave ablation of malignant liver tumors: comparison of stereotactic and conventional manual guidance

In this study, we compare the primary efficacy of computed tomography-navigated stereotactic guidance to that of manual guidance for percutaneous microwave ablation of liver malignancies. In total, 221 patients (140, 17, and 64 with hepatocellular carcinoma, cholangiocellular carcinoma, and liver metastases, respectively) with 423 treated liver lesions underwent microwave ablation (MWA). Manual guidance (M) and stereotactic guidance (S) were used for 136 and 287 lesions, respectively. The primary endpoint was the primary efficacy and the secondary endpoint was the radiation dose. A generalised estimating equation was applied to analyse the correlation between the primary efficacy (lesion basis) and the type of guidance, size and location of lesion. The primary efficacy rate was significantly higher in the S-group (84.3%) than in the M-group (75.0%, p = 0.03). Lesion size > 30 mm was negatively correlated with the efficacy rate (odds ratio 0.38; 95% confidence interval 0.20–0.74). Stereotactic guidance was associated with a significantly lower dose length product (p < 0.01). In this retrospective study, percutaneous microwave ablation under stereotactic guidance exhibited significantly greater primary efficacy than conventional manual guidance.