Determinants of radiation exposure during mobile cone-beam CT-guided robotic-assisted bronchoscopy.

BACKGROUND AND OBJECTIVE: Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB. METHODS: Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models. RESULTS: A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 µSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose. CONCLUSION: The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.

The feasibility of a novel 3D-Printed patient specific cutting guide for extended trochanteric osteotomies.

BACKGROUND: The extended trochanteric osteotomy (ETO) is a surgical technique utilized to expose the intramedullary canal of the proximal femur, protect the soft tissues and promote reliable healing. However, imprecise execution of the osteotomy can lead to fracture, soft tissue injury, non-union, and unnecessary morbidity. We developed a technique to create patient specific, 3D-printed cutting guides to aid in accurate positioning of the ETO and improve osteotomy quality and outcomes. METHODS: Patient specific cutting guides were created based on CT scans using Synopysis Simpleware ScanIP and Solidworks. Custom 3D printed cutting guides were tested on synthetic femurs with foam cortical shells and on cadaveric femurs. To confirm accuracy of the osteotomies, dimensions of the performed osteotomies were compared to the virtually planned osteotomies. RESULTS: Use of the patient specific ETO cutting guides resulted in successful osteotomies, exposing the femoral canal and the femoral stem both in synthetic sawbone and cadaveric testing. In cadaveric testing, the guides allowed for osteotomies without fracture and cuts made using the guide were accurate within 6 percent error from the virtually planned osteotomy. CONCLUSION: The 3D-printed patient specific cutting guides used to aid in ETOs proved to be accurate. Through the iterative development of cutting guides, we found that a simple design was key to a reliable and accurate guide. While future clinical trials in human subjects are needed, we believe our custom 3D printed cutting guide design to be effective at aiding in performing ETOs for revision total hip arthroplasty surgeries.

The incremental contribution of mobile cone-beam computed tomography to the tool-lesion relationship during shape-sensing robotic-assisted bronchoscopy.

Introduction: This study aims to answer the question of whether adding mobile cone-beam computed tomography (mCBCT) imaging to shape-sensing robotic-assisted bronchoscopy (ssRAB) translates into a quantifiable improvement in the tool-lesion relationship. Methods: Data from 102 peripheral lung lesions with ≥2 sequential mCBCT orbital spins and from 436 lesions with 0-1 spins were prospectively captured and retrospectively analysed. The primary outcome was the tool-lesion relationship status across the first and the last mCBCT spins. Secondary outcomes included 1) the change in distance between the tip of the sampling tool and the centre of the lesion between the first and the last spins and 2) the per-lesion diagnostic yield. Results: Compared to lesions requiring 0-1 spins, lesions requiring ≥2 spins were smaller and had unfavourable bronchus sign and intra-operative sonographic view. On the first spin, 54 lesions (53%) were designated as non-tool-in-lesion (non-TIL) while 48 lesions (47%) were designated as TIL. Of the 54 initially non-TIL cases, 49 (90%) were converted to TIL status by the last spin. Overall, on the last spin, 96 out of 102 lesions (94%) were defined as TIL and six out of 102 lesions (6%) were defined as non-TIL (p<0.0001). The mean distance between the tool and the centre of the lesion decreased from 10.4 to 6.6 mm between the first and last spins (p<0.0001). The overall diagnostic yield was 77%. Conclusion: Targeting traditionally challenging lung lesions, intra-operative volumetric imaging allowed for the conversion of 90% of non-TIL status to TIL. Guidance with mCBCT resulted in a significant decrease in the distance between the tip of the needle to lesion centre.

Medical malpractice and intracranial hemorrhages in the U.S.: An analysis of 121 cases over 35 years.

Introduction: Though all physicians are at risk for medical malpractice litigation, those in surgical specialties, particularly neurosurgeons, are at increased risk. Because intracranial hemorrhages are a life-threatening and commonly misdiagnosed condition, the aim of this study is to identify and increase awareness of factors associated with litigation in cases of intracranial hemorrhages. Methods: The online legal database Westlaw was utilized to query public litigation cases related to the management of intracranial hemorrhages between 1985 and 2020. Various search terms were used to identify cases, and the following variables were extracted: plaintiff demographics, defendant specialty, trial year, court type, location, reason for litigation, plaintiff medical complaints, trial outcomes, and payouts for both verdicts and settlements. Comparative analysis was performed between cases decided in favor of the plaintiff and in favor of the defendant. Results: A total of 121 cases met inclusion criteria. The most common type of hemorrhage was subarachnoid (65.3%), and the most common cause of hemorrhage was cerebral aneurysm/vascular malformation (37.2%). Most cases were brought against a hospital or healthcare system (60.3%), followed by emergency medicine physicians (33.1%), family medicine physicians (10.7%), and neurosurgeons (6.6%). Failure to diagnose was the most common reason for litigation (84.3%). Cases most frequently resulted in verdicts favoring the defense (48.8%), followed by settlements (35.5%). Plaintiffs were found to be significantly younger in cases ruled in favor of the plaintiff than in cases ruled in favor of the defense (p = 0.014). Cases ruled in favor of the plaintiff were also significantly more likely to involve a neurologist (p = 0.029). Conclusions: Most cases of intracranial hemorrhage resulting in malpractice litigation were classified as subarachnoid hemorrhages and caused by aneurysm/vascular malformation. Most cases were brought against hospital systems, and failure to diagnose was the most common reason for litigation. Cases resulting in verdicts in favor of the plaintiff were significantly more likely to involve younger plaintiffs and neurologists.

An accessible method for screening aerosol filtration identifies poor-performing commercial masks and respirators.

BACKGROUND: The COVID-19 pandemic has presented an acute shortage of regulation-tested masks. Many of the alternatives available to hospitals have not been certified, leaving uncertainty about their ability to properly protect healthcare workers from SARS-CoV-2 transmission. OBJECTIVE: For situations where regulatory methods are not accessible, we present experimental methods to evaluate mask filtration and breathability quickly via cost-effective approaches (e.g., ~$2000 USD) that could be replicated in communities of need without extensive infrastructure. We demonstrate the need for screening by evaluating an existing diverse inventory of masks/respirators from a local hospital. METHODS: Two experimental approaches are presented to examine both aerosol filtration and flow impedance (i.e., breathability). For one of the approaches ("quick assessment"), screening for appropriate filtration could be performed under 10 min per mask, on average. Mask fit tests were conducted in tandem but are not the focus of this study. RESULTS: Tests conducted of 47 nonregulation masks reveal variable performance. A number of commercially available masks in hospital inventories perform similarly to N95 masks for aerosol filtration of 0.2 µm and above, but there is a range of masks with relatively lower filtration efficiencies (e.g., <90%) and a subset with poorer filtration (e.g., <70%). All masks functioned acceptably for breathability, and impedance was not correlated with filtration efficiency. SIGNIFICANCE: With simplified tests, organizations with mask/respirator shortages and uncertain inventories can make informed decisions about use and procurement.