Autonomous Medical Needle Steering In Vivo

The use of needles to access sites within organs is fundamental to many interventional medical procedures both for diagnosis and treatment. Safe and accurate navigation of a needle through living tissue to an intra-tissue target is currently often challenging or infeasible due to the presence of anatomical obstacles in the tissue, high levels of uncertainty, and natural tissue motion (e.g., due to breathing). Medical robots capable of automating needle-based procedures in vivo have the potential to overcome these challenges and enable an enhanced level of patient care and safety. In this paper, we show the first medical robot that autonomously navigates a needle inside living tissue around anatomical obstacles to an intra-tissue target. Our system leverages an aiming device and a laser-patterned highly flexible steerable needle, a type of needle capable of maneuvering along curvilinear trajectories to avoid obstacles. The autonomous robot accounts for anatomical obstacles and uncertainty in living tissue/needle interaction with replanning and control and accounts for respiratory motion by defining safe insertion time windows during the breathing cycle. We apply the system to lung biopsy, which is critical in the diagnosis of lung cancer, the leading cause of cancer-related death in the United States. We demonstrate successful performance of our system in multiple in vivo porcine studies and also demonstrate that our approach leveraging autonomous needle steering outperforms a standard manual clinical technique for lung nodule access.Comment: 22 pages, 6 figure

Electromagnetic Transthoracic Nodule Localization for Minimally Invasive Pulmonary Resection

Background: Increased use of chest computed tomography and the institution of lung cancer screening have increased the detection of ground-glass and small pulmonary nodules. Intraoperative localization of these lesions via a minimally invasive thoracoscopic approach can be challenging. We present the feasibility of perioperative transthoracic percutaneous nodule localization using a novel electromagnetic navigation platform. Methods: This is a multicenter retrospective analysis of a prospectively collected database of patients who underwent perioperative electromagnetic transthoracic nodule localization before attempted minimally invasive resection between July 2016 and March 2018. Localization was performed using methylene blue or a mixture of methylene blue and the patient's blood (1:1 ratio). Patient, nodule, and procedure characteristics were collected and reported. Results: Thirty-one nodules were resected from 30 patients. Twenty-nine of 31 nodules (94%) were successfully localized. Minimally invasive resection was successful in 93% of patients (28/30); 7% (2/30) required conversion to thoracotomy. The median nodule size was 13 mm (interquartile range 25%-75%, 9.5-15.5), and the median depth from the surface of the visceral pleura to the nodule was 10 mm (interquartile range 25%-75%, 5.0-15.9). Seventy-one percent (22/31) of nodules were malignant. No complications associated with nodule localization were reported. Conclusions: The use of intraoperative electromagnetic transthoracic nodule localization before thoracoscopic resection of small and/or difficult to palpate lung nodules is safe and effective, potentially eliminating the need for direct nodule palpation. Use of this technique aids in minimally invasive localization and resection of small, deep, and/or ground-glass lung nodules

Feasibility of a prototype carbon nanotube enabled stationary digital chest tomosynthesis system for identification of pulmonary nodules by pulmonologists

Background: Screen detected and incidental pulmonary nodules are increasingly common. Current guidelines recommend tissue sampling of solid nodules >8 mm. Bronchoscopic biopsy poses the lowest risk but is paired with the lowest diagnostic yield when compared to CT-guided biopsy or surgery. A need exists for a safe, mobile, low radiation dose, intra-procedural method to localize biopsy instruments within target nodules. This retrospective cross sectional reader feasibility study evaluates the ability of clinicians to identify pulmonary nodules using a prototype carbon nanotube radiation enabled stationary digital chest tomosynthesis system. Methods: Patients with pulmonary nodules on prior CT imaging were recruited and consented for imaging with stationary digital chest tomosynthesis. Five pulmonologists of varying training levels participated as readers. Following review of patient CT and a thoracic radiologist’s interpretation of nodule size and location the readers were tasked with interpreting the corresponding tomosynthesis scan to identify the same nodule found on CT. Results: Fifty-five patients were scanned with stationary digital chest tomosynthesis. The median nodule size was 6 mm (IQR =4–13 mm). Twenty nodules (37%) were greater than 8 mm. The radiation entrance dose for s-DCT was 0.6 mGy. A significant difference in identification of nodules using s-DCT was seen for nodules <8 vs. ≥8 mm in size (57.7% vs. 90.9%, CI: −0.375, −0.024; P<0.001). Inter-reader agreement was fair, and better for nodules ≥8 mm [0.278 (SE =0.043)]. Conclusions: With system and carbon nanotube array optimization, we hypothesize the detection rate for nodules will improve. Additional study is needed to evaluate its use in target and tool co-localization and target biopsy

A bronchoscopy-associated pseudo-outbreak of Mycobacterium mucogenicum traced to use of contaminated ice used for bronchoalveolar lavage

Clonal Mycobacterium mucogenicum isolates (determined by molecular typing) were recovered from 19 bronchoscopic specimens from 15 patients. None of these patients had evidence of mycobacterial infection. Laboratory culture materials and bronchoscopes were negative for Mycobacteria. This pseudo-outbreak was caused by contaminated ice used to provide bronchoscopic lavage. Control was achieved by transitioning to sterile ice

Incidence and clinical relevance of non-small cell lung cancer lymph node micro-metastasis detected by staging endobronchial ultrasound-guided transbronchial needle aspiration

Background: Approximately twenty percent of lymph node (LN) negative non-small cell lung cancer (NSCLC) patients who undergo curative intent surgery have pan-cytokeratin immunohistochemistry (IHC)-detectable occult micro-metastases (MMs) in resected LNs. The presence of the MMs in NSCLC is associated worsened outcomes. As a substantial proportion of NSCLC LN staging is conducted using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), we sought to determine the frequency of detection of occult MMs in EBUS-TBNA specimens and to evaluate the impact of MMs on progression-free and overall survival. Methods: We performed retrospective IHC staining for pan-cytokeratin of EBUS-TBNA specimens previously deemed negative by a cytopathologist based on conventional hematoxylin and eosin staining. The results were correlated with clinical variables, including survival outcomes. Results: Of 887 patients screened, 44 patients were identified meeting inclusion criteria with sufficient additional tissue for testing. With respect to the time of the EBUS-TBNA procedure, 52% of patients were clinical stage I, 34% clinical stage II, and clinical 14% stage IIIa NSCLC. Three patients (6.8%) were found to have cytokeratin positive MMs. All 3 MMs detected were at N2 LN stations. The presence of MMs was associated with significantly decreased progression-free (median 210 vs. 1,293 days, P=0.0093) and overall survival (median 239 vs. 1,120 days, P=0.0357). Conclusions: Occult LN MMs can be detected in EBUS-TBNA specimens obtained during staging examinations and are associated with poor clinical outcomes. If prospectively confirmed, these results have significant implications for EBUS-TBNA specimen analyses and possibly for the NSCLC staging paradigm

A Quality Improvement Intervention to Reduce Indwelling Tunneled Pleural Catheter Infection Rates

The indwelling tunneled pleural catheter has altered the management of patients with dyspnea related to malignant pleural effusions. However, indwelling tunneled pleural catheter placement does not remain free from risk. The most commonly reported risk is infection. The aim of this paper is to describe our continuous quality improvement program for infection rate recognition, the process changes implemented for improvement, and subsequent outcomes. All patients undergoing indwelling tunneled pleural catheter placement at The Johns Hopkins Medical Institutions between May 2009 and April 2014 were identified. The primary outcome was the incidence of infection within the preintervention and intervention cohorts. Intervention was identified as use of preoperative antibiotics, full sterile draping, and limiting placement to a single defined location. A total of 225 indwelling tunneled pleural catheter placements were performed in 201 patients during the study period, and the overall infection rate was 5.8%. During the preintervention period, 134 placements were performed, and 91 placements occurred during the intervention period. A preintervention infection rate was identified as 8.2%, with a significant decrease to 2.2% (P = 0.049) within the intervention cohort. The use of a continuous quality improvement program to review indwelling tunneled pleural catheter practices can result in the identification of infectious complications and lead to implementation of measures to improve patient outcomes

Comparison of Pleural Pressure Measuring Instruments

OBJECTIVE: The objective of this study was to compare the accuracy of a handheld digital manometer (DM) and U-tube (UT) manometer with an electronic transducer (ET) manometer during thoracentesis. METHODS: Thirty-three consecutive patients undergoing thoracentesis were enrolled in the study. Pleural pressure (Ppl) measurements were made using a handheld DM (Compass; Mirador Biomedical), a UT water manometer, and an ET (reference instrument). End-expiratory Ppl was recorded aft er catheter insertion, aft er each aspiration of 240 mL, and prior to catheter removal. Volume of fluid removed, symptoms during thoracentesis, pleural elastance, and pleural fluid chemistry were also evaluated. RESULTS: A total of 594 Ppl measurements were made in 30 patients during their thoracenteses. There was a strong linear correlation coefficient between elastance for the DM and ET (r - 0.9582, P < .001). Correlation was poor between the UT and ET (r - 0.0448, P - .84). Among the 15 patients who developed cough, recorded ET pressures ranged from -9 to +9 cm H2O at the time of symptom development, with a mean (SD) of -2.93 (4.89) cm H2O. ET and DM measurements among those patients with cough had a low correlation between these measurements (R-2 = 0.104, P = .24). Nine patients developed chest discomfort and had ET pressures that ranged from -26 to +6 cm H2O, with a mean (SD) of -7.89 (9.97) cm H2O. CONCLUSIONS: The handheld DM provided a valid and easy-to-use method to measure Ppl during thoracentesis. Future studies are needed to investigate its usefulness in predicting clinically meaningful outcomes

Indwelling tunneled pleural catheters for refractory hepatic hydrothorax in patients with cirrhosis: a multicenter study

Background: The outcome of indwelling pleural catheter (IPC) use in hepatic hydrothorax (HH) is unclear. This study aimed to review the safety and feasibility of the IPC in patients with refractory HH. Methods: A retrospective multicenter study of patients with HH from January 2010 to December 2016 was performed. Inclusion criteria were refractory HH treated with an IPC and an underlying diagnosis of cirrhosis. Records were reviewed for patient demographics, operative reports, and laboratory values. The Kaplan-Meier method was used to estimate catheter time to removal. The Cox proportional hazard model was used to evaluate for independent predictors of pleurodesis and death. Results: Seventy-nine patients were identified from eight institutions. Indication for IPC placement was palliation in 58 patients (73%) and bridge to transplant in 21 patients (27%). The median in situ dwell time of all catheters was 156 days (range, 16-1,978 days). Eight patients (10%) were found to have pleural space infection, five of whom also had catheter-site cellulitis. Two patients (2.5%) died secondary to catheter-related sepsis. Catheter removal secondary to spontaneous pleurodesis was achieved in 22 patients (28%). Median time from catheter insertion to pleurodesis was 55 days (range, 10-370 days). Older age was an independent predictor of mortality on multivariate analysis (hazard ratio, 1.05; P = .01). Conclusions: We present, to our knowledge, the first multicenter study examining outcomes related to IPC use in HH. Ten percent infection risk and 2.5% mortality were identified. IPC placement may be a reasonable clinical option for patients with refractory HH, but it is associated with significant adverse events in this morbid population.</p