Postprocedure Computed Tomography Scans Research Articles

Stereotactic brain Interventions: Identifying risks for biopsy failures and hemorrhage

BackgroundThe advent of computed tomography (CT) and magnetic resonance imaging (MRI) has revolutionized stereotactic brain interventions, which enabled precise targeting of deep brain structures and enhanced patient safety in modern neurosurgery. This study aims to investigate the risk factors associated with biopsy failure and hemorrhage in CT-guided brain stereotactic surgeries. MethodsIn the current study, we present a retrospective descriptive analysis of cases that showed biopsy failures and hemorrhage after CT-guided stereotactic brain biopsy surgeries at our department from January 2019 to January 2021. Biopsies were obtained using a Sedan-type needle. ResultsOut of the 80 patients who underwent CT-guided stereotactic surgeries, two patients (2.5 %) experienced biopsy failure, necessitating a repeat procedure. There was a notably higher risk of biopsy failure when fewer than four biopsy attempts were made (adjusted odds ratio = 6.4, 95 % CI 1.8 to 16.7). A postprocedural CT scan revealed intracranial hemorrhage in five patients (6.25 %); four of these cases were silent, with no accompanying neurological complications. Four out of the five hemorrhage cases were associated with astrocytoma. ConclusionsStereotactic surgery provides a precise and minimally invasive approach to target lesions with a relatively low risk of biopsy failures and hemorrhage.

Transcatheter closure of postsurgical aortic pseudoaneurysms guided by three-dimensional image reconstruction: asingle-centre experience.

Postsurgical thoracic aortic pseudoaneurysms (PTAPs) are apotentially lethal complication after cardiac or aortic surgery. Surgical management can pose achallenge with high in-hospital mortality rates. Transcatheter closure is aless-invasive alternative treatment option for selected patients, although current experience is limited. We aimed to evaluate procedural and imaging outcomes of our first 11cases of transcatheter PTAP closure with the use of closure devices. Patients with ahigh operative risk who underwent transcatheter PTAP closure at our centre from 2019 to 2021 were retrospectively included. Suitability was evaluated on preprocedural computed tomography (CT) scans and three-dimensional (3D) reconstructions. All procedures were performed in the catheterisation laboratory. Intraprocedural aortography and postprocedural CT scans with 3D reconstructions were used to evaluate PTAP occlusion. Eleven consecutive patients with ahigh operative risk and ahistory of cardiac/aortic surgery who underwent transcatheter PTAP closure were included. PTAPs were predominantly located at the proximal or distal anastomosis of asupracoronary ascending aortic vascular graft or Bentall prosthesis (82%). Implanted closure devices included Amplatzer Valvular PlugIII (82%), Amplatzer septal occluder (9%) and Occlutech atrial septal defect occluder (9%). No periprocedural complications occurred. After device deployment, residual flow was absent on aortography in 64% and minimal residual flow was present in 36% of patients. Subtotal or total occlusion of the PTAP on follow-up CT ranged between 45% and 73%. Although subtotal or total occlusion of the PTAP was found at follow-up in only 45-73% of cases, transcatheter PTAP closure guided by preprocedural 3D reconstructions can offer avaluable minimally invasive primary treatment option for patients who otherwise would face ahigh-risk reoperation.

Computed tomography-guided stereotactic surgery in the management of brain lesions: A single-center experience.

The present study presents our experience with computed tomography (CT)-guided stereotactic surgery in managing deep-seated brain lesions and provides a background in the expanding fields of morphological stereotactic neurosurgery. We conducted this retrospective cohort study on 80 patients managed at the Department of Neurosurgery, Zagazig University Hospitals, Zagazig, Egypt, between January 2019 to January 2021. We targeted patients with morphological stereotactic surgeries performed as the primary management modality of their treatment. A total of 80 patients, with a mean age of 44.3 years, were included in the study. The stereotactic targets were supratentorial in 71 patients (88.75%), infratentorial in seven patients (8.75%), and both supraand infratentorial in two patients (2.5%). The lesions showed enhancements with IV contrast in 55 patients (68.75%). Stereotactic procedures were performed under local anesthesia in 64 patients and general anesthesia in 16 patients. Of the 80 stereotactic procedures, 52 were biopsies (65%). We observed a significant improvement in the postoperative Karnofsky performance score compared to the postoperative score (63.4 ± 19.8 vs. 56.7 ± 15.4, P = 0.001). The level of agreement between clinical, radiological, and final pathological diagnosis was assessed; it was complete in 47.5% of the patients. The postprocedural CT scan demonstrated intracranial hemorrhage in five patients (6.25%); four (5%) were silent with no neurological complications. This study provided evidence that the stereotactic procedure is easy to perform, accurate in targeting the lesion, and spares patients from undergoing major surgical procedures. Stereotactic applications of spontaneous intracerebral hemorrhage, deep-seated abscesses, encysted tumors, or medically refractory benign intracranial hypertension can improve the outcome even in medically high-risk patients.

CT features and risk factors of pulmonary cement embolism after vertebroplasty or kyphoplasty in patients with vertebral compression fracture: a retrospective cohort study.

Pulmonary cement embolism (PCE) caused by cement leakage is one of the complications of percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). The aim of our study was to explore the imaging features on computed tomography (CT) and analyze the risk factors of PCE in patients with a vertebral compression fracture to compare the incidences of PCE caused by PVP and PKP. In this single-center, retrospective study, 373 patients (96 males and 277 females; mean age 76.2±9.4 years) from January 2017 to December 2020 who underwent PVP or PKP for treatment of vertebral compression fracture in the China-Japan Friendship Hospital were retrospectively included. Their clinical data were recorded, and their postprocedural chest CT scans were reviewed and evaluated for PCE. Of the 373 patients, 258 patients underwent PVP while the other 115 underwent PKP. PCE was found on the postprocedural chest CT scans in 64 patients (17.2%), including 47 patients with PVP and 17 patients with PKP. The incidence of PCE of PVP and PKP was similar (χ2=0.660; P=0.460). The typical CT findings of PCE were multiple linear or branching radiopaque densities in pulmonary arteries. The upper lobes of bilateral lungs were the most frequently involved. In addition, postprocedural chest CT demonstrated that 103 cases had cement emboli in the azygos vein, and 8 cases had cement emboli in the inferior vena cava. Binary logistic regression analysis demonstrated that PVP or PKP in the T9 vertebra [odds ratio (OR) =4.222; 95% CI: 1.490-11.966] and cement emboli in the azygos vein (OR =7.647; 95% CI: 3.937-14.856) or the inferior vena cava (OR =42.701; 95% CI: 7.525-242.302) were the risk factors of PCE. The incidence of PCE during PVP or PKP was 17.2%. Postprocedural chest CT clearly showed PCE as branching hyperdense or radiopaque lesions confined within the pulmonary artery courses. PVP or PKP in the T9 vertebra and cement emboli in the azygos vein or the inferior vena cava were risk factors for PCE.

Cement leakage during vertebroplasty: comparison between intact and wall disruption in spinal metastases.

Percutaneous vertebroplasty (PVP) is an effective measure for painful metastases or impending pathological fractures of the spine with cement leakages being the most frequent complication. Posterior extrusion of cement into the spinal canal may result in neurological symptoms and deficits. To compare the occurrence of intraspinal canal cement leakage between vertebrae with posterior wall disruption and vertebrae without posterior wall disruption. A single-center retrospective study was conducted of all PVP for spine metastases between June 2020 and November 2021. All leaks were analyzed by a postprocedural computed tomography scan or cone-beam computed tomography. A total of 77 patients with 143 vertebrae treated by PVP were included. Posterior wall disruption was observed in 64 (44.8%) vertebrae while 79 (55.2%) had a complete posterior wall. Spinal canal cement leakage occurred in 36 (25.2%) vertebrae and was comparable in both groups, occurring in 16 (25.0%) vertebrae with posterior wall disruption and 20 (25.3%) vertebrae without posterior wall disruption (P = 1). No risk factors for spinal canal leakage were found in the univariate and multivariate analyses. One spinal leak was symptomatic with intercostal neuralgia. Our results suggest that an incomplete vertebral posterior wall does not increase the rate of spinal canal cement leakage during PVP.

Assessing the Hemodynamic Impact of Anterior Leaflet Laceration in Transcatheter Mitral Valve Replacement: An in silico Study.

BackgroundA clinical study comparing the hemodynamic outcomes of transcatheter mitral valve replacement (TMVR) with vs. without Laceration of the Anterior Mitral leaflet to Prevent Outflow Obstruction (LAMPOON) has never been designed nor conducted.AimsTo quantify the hemodynamic impact of LAMPOON in TMVR using patient-specific computational (in silico) models.MaterialsEight subjects from the LAMPOON investigational device exemption trial were included who had acceptable computed tomography (CT) data for analysis. All subjects were anticipated to be at prohibitive risk of left ventricular outflow tract (LVOT) obstruction from TMVR, and underwent successful LAMPOON immediately followed by TMVR. Using post-procedure CT scans, two 3D anatomical models were created for each subject: (1) TMVR with LAMPOON (performed procedure), and (2) TMVR without LAMPOON (virtual control). A validated computational fluid dynamics (CFD) paradigm was then used to simulate the hemodynamic outcomes for each condition.ResultsLAMPOON exposed on average 2 ± 0.6 transcatheter valve cells (70 ± 20 mm2 total increase in outflow area) which provided an additional pathway for flow into the LVOT. As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak LVOT velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 0.4 ± 0.3 m/s (14 ± 7% improvement, p = 0.006), 7.6 ± 10.9 mmHg (31 ± 17% improvement, p = 0.01), and 0.2 ± 0.1 cm2 (17 ± 9% improvement, p = 0.002), respectively.ConclusionThis was the first study to permit a quantitative, patient-specific comparison of LVOT hemodynamics following TMVR with and without LAMPOON. The LAMPOON procedure achieved a critical increment in outflow area which was effective for improving LVOT hemodynamics, particularly for subjects with a small neo-left ventricular outflow tract (neo-LVOT).

Image Registration-Based Method for Reconstructing Transcatheter Heart Valve Geometry from Patient-Specific CT Scans.

Accurate reconstruction of transcatheter aortic valve (TAV) geometries and other stented cardiac devices from computed tomography (CT) images is challenging, mainly associated with blooming artifacts caused by the metallic stents. In addition, bioprosthetic leaflets of TAVs are difficult to segment due to the low signal strengths of the tissues. This paper describes a method that exploits the known device geometry and uses an image registration-based reconstruction method to accurately recover the in vivo stent and leaflet geometries from patient-specific CT images. Error analyses have shown that the geometric error of the stent reconstruction is around 0.1mm, lower than 1/3 of the stent width or most of the CT scan resolutions. Moreover, the method only requires a few human inputs and is robust to input biases. The geometry and the residual stress of the leaflets can be subsequently computed using finite element analysis (FEA) with displacement boundary conditions derived from the registration. Finally, the stress distribution in self-expandable stents can be reasonably estimated by an FEA-based simulation. This method can be used in pre-surgical planning for TAV-in-TAV procedures or for in vivo assessment of surgical outcomes from post-procedural CT scans. It can also be used to reconstruct other medical devices such as coronary stents.

INTRACRANIAL EMBOLIZATION: A RARE COMPLICATION

We report a case of a rare complication: aortic pseudoaneurysm rupture after embolization of an intracranial aneurysm in a 62 –year- old patient with spontaneous subarachnoid hemorrhage, presented with chest pain and shortness of breath the fourth day after the procedure. The intracranial aneurysm was embolized with no intraoperative complications, and a postprocedural CT (computed tomography) scan showed no signs of intracranial rebleeding, ischemic lesions, or hydrocephalus. Cardiosurgical treatment was not indicated for the aortic pseudoaneurysm rupture.

Abstract 12848: Patient-Specific in silico Models Demonstrate Hemodynamic Effect of LAMPOON in Transcatheter Mitral Valve Replacement

Introduction: The purpose of this study was to investigate the hemodynamic impact of LAMPOON (Laceration of the Anterior Mitral leaflet to Prevent Outflow ObstructioN) in transcatheter mitral valve replacement (TMVR) using patient-specific in silico modeling. Methods: Eight subjects from the LAMPOON investigational device exemption trial were included. All subjects were at prohibitive risk of outflow tract obstruction from TMVR based on computed tomography (CT), and underwent successful LAMPOON immediately followed by TMVR. A validated computational fluid dynamics (CFD) model was used to compare simulated hemodynamics and 3D flow patterns between two modeled conditions: 1) TMVR with LAMPOON and 2) TMVR without LAMPOON. Using the post-procedure CT scans, anatomical models of TMVR with LAMPOON were created for each subject. The open transcatheter valve cells were then virtually closed to model TMVR without LAMPOON for each subject. Finally, CFD was performed for each condition to simulate the systolic flow fields. Results: As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 13 ± 6% (p=0.004), 28 ± 14% (p=0.008), and 15 ± 8% (p=0.002), respectively. LAMPOON provided flow communication through exposed cells of the transcatheter valve, thereby decreasing the flow constriction and reducing flow stasis in the vicinity of the neo-LVOT (Figure). The hemodynamic benefit of LAMPOON was observed to be greater in subjects with a smaller neo-LVOT area measured post-implant (p<0.001). Conclusions: In silico modeling allowed for a quantitative patient-specific comparison of TMVR with and without LAMPOON, which is impossible to study clinically. The LAMPOON procedure improved simulated hemodynamics in all subjects, with a greater hemodynamic impact observed in subjects with a smaller post-implant neo-LVOT area.

Orthogonal external ventricular drain (EVD) trajectory from burr holes sited by junior neurosurgical staff is superior to freehand placement: An in-silico model

External ventricular drain (EVD) or ventriculostomy placement is one of the most common neurosurgical procedures performed worldwide and is associated with complications including haemorrhage, malposition and infection. Several authors have attempted to define an ideal trajectory for placement, and scalp-mounted guidance devices have been devised to exploit the theoretical ideal orthogonal trajectory from the scalp to the lateral ventricles. However, uptake has been limited due to lack of demonstrated superiority to freehand placement. Previous modelling studies have failed to include a true-to-life sample of patients undergoing EVD insertion and excluded cases with midline shift or non-hydrocephalus indications. Further, none have attempted to model the orthogonal insertion of EVD via actual burr holes placed by junior neurosurgical staff. In our report of 58 cases of frontal EVD insertion in a low-volume Australian neurosurgical unit freehand EVD insertion resulted in acceptable placement in the ipsilateral frontal horn in 62% of cases, any ventricle in 22%, and in eloquent or non-eloquent brain in 16% of cases. The modelled orthogonal trajectory from the same burr holes, using post-procedural computed tomography scans and the S8 Stealth Station (Medtronic), resulted in superior placement; 80% in the ipsilateral frontal horn and 20% contralateral (p = 0.007). There were no significant malpositions associated with the modelled trajectories. In our series, 18% of freehand catheters required multiple placement attempts. In conclusion, our data suggests that an orthogonal trajectory may result in improved EVD positioning compared to freehand placement.

Augmented Reality for Retrosigmoid Craniotomy Planning.

While medical imaging data have traditionally been viewed on two-dimensional (2D) displays, augmented reality (AR) allows physicians to project the medical imaging data on patient's bodies to locate important anatomy. We present a surgical AR application to plan the retrosigmoid craniotomy, a standard approach to access the posterior fossa and the internal auditory canal. As a simple and accurate alternative to surface landmarks and conventional surgical navigation systems, our AR application augments the surgeon's vision to guide the optimal location of cortical bone removal. In this work, two surgeons performed a retrosigmoid approach 14 times on eight cadaver heads. In each case, the surgeon manually aligned a computed tomography (CT)-derived virtual rendering of the sigmoid sinus on the real cadaveric heads using a see-through AR display, allowing the surgeon to plan and perform the craniotomy accordingly. Postprocedure CT scans were acquired to assess the accuracy of the retrosigmoid craniotomies with respect to their intended location relative to the dural sinuses. The two surgeons had a mean margin of d avg = 0.6 ± 4.7 mm and d avg = 3.7 ± 2.3 mm between the osteotomy border and the dural sinuses over all their cases, respectively, and only positive margins for 12 of the 14 cases. The intended surgical approach to the internal auditory canal was successfully achieved in all cases using the proposed method, and the relatively small and consistent margins suggest that our system has the potential to be a valuable tool to facilitate planning a variety of similar skull-base procedures.

Psoas hematoma due to segmental vessel injury leads to paresis following CT-guided biopsy of lumbar vertebrae: A case report

Background: Percutaneous bone biopsy is the first-line procedure for obtaining a tissue diagnosis to confirm focal, diffuse vertebral, and/or paravertebral metastatic lesions. Percutaneous bone biopsy to evaluate metastatic disease can be performed under fluoroscopy, ultrasonography, magnetic resonance (MR) imaging, and computed tomography (CT). Notably, CT-scans best direct and demonstrate the needle position for these procedures, decreasing the risk of injury to critical adjacent structures (e.g. major vessels, nerve roots). Hemorrhagic complication to lumbar segmental arteries following needle biopsy are uncommon; only a few cases have been reported. Although percutaneous bone biopsy is typically safe when performed utilizing computed tomography (CT) guidance, here we encountered a 60-year-old-female who developed a L4 lumbar segmental artery psoas hematoma following this procedure requiring emergent embolization.Case Description: A 60-year-old female, with a history of breast cancer, underwent a CT-guided core needle biopsy of an L4 lytic lesion (e.g., likely a metastasis). This acutely resulted in the onset of radicular leg pain and weakness. When the postprocedural CT scan demonstrated a large psoas hematoma attributed to laceration of the left posterior L4 segmental artery, the patient required emergent embolization. Following this procedure, she exhibited a fully neurological recovery.Conclusion: Following a CT-guided L4 vertebral biopsy to document metastatic breast carcinoma, a 60-year-old patient developed an immediate postprocedure CT-documented psoas hematoma due to laceration of the left posterior L4 segmental artery. Following emergent embolization, the patient recovered full neurological function.

Methylene Blue/Collagen Mixture for CT-Guided Presurgical Lung Nodule Marking: High Efficacy and Safety

PurposeTo assess outcomes of computed tomography (CT)-guided methylene blue/collagen marking of preoperative lung nodules before video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracic surgery (RATS). Materials and MethodsA retrospective cohort study assessing 25 methylene blue/collagen solution CT-guided lung nodule localization procedures on 26 nodules in 25 patients was performed. The procedures were performed by a fellowship-trained radiologist 1–2 hours before scheduled surgery under local anesthesia. Approximately 4–6 ml of methylene blue/collagen solution was injected in a perinodular location under CT guidance with a 19-gauge trocar needle and along the track to the visceral pleural surface. Post-procedural CT images confirmed appropriate lung nodule location marking. ResultsPerinodular CT-guided trocar needle placement was achieved in all marking procedures (n = 26/26). Increased consolidation near the target nodule was also demonstrated in all patients on the post-procedural localized CT scans. One patient with moderate emphysema developed a small to moderate-sized pneumothorax (∼20%–30%), and an 8-Fr thoracentesis catheter was placed under CT guidance before surgery. There was no bleeding or hemoptysis in any patient. Methylene blue/collagen solution was readily visible by the thoracic surgeon in association with all target nodules. One patient required conversion to open procedure due to the proximal portion of the right lower lobe pulmonary artery segmental branch. Of the 26 identified nodules, pathology specimens confirmed the adequacy of nodule resection in all cases. ConclusionsPreoperative CT-guided methylene blue/collagen solution injection offers a safe and highly effective technique for marking subpleural lung nodules undergoing VATS or RATS.

Three-Dimensional Printed Targeting Device for Scaphoid Fracture Fixation.

Background: Percutaneous guide wire insertion for scaphoid screw fixation can be challenging and often requires multiple attempts with significant radiation exposure to the surgical team. A 3-dimensional (3D) printed targeting device has the potential to reduce procedure time and intraoperative radiation exposure. Methods: Our targeting device protocol included a preprocedure computed tomography (CT) scan of a casted cadaver wrist, followed by 3D printing of a customized targeting guide. In a comparison trial, seven orthopedic surgery residents performed percutaneous scaphoid guide wire insertion on different cadaver specimens by both freehand technique and using our targeting device. Radiation exposure and procedure times were compared. All specimens underwent postprocedure CT to assess Kirschner wire (K-wire) accuracy, determined by central third placement. Pre- and postprocedure CT scans from the targeting device group were co-registered to compare planned and actual K-wire trajectories. Results: Using the freehand technique, mean fluoroscopy time was 120 seconds (standard deviation: ±53 seconds) generating 2.45 milligray of radiation. Average procedure time was 21 minutes with a mean of 6.4 (range: 3-9) insertion attempts. A single insertion attempt was made using the targeting device with an average procedure time of 30 seconds and no fluoroscopy exposure. Four K-wires were placed within the central scaphoid in both groups. Using the targeting device, average linear deviation from the planned trajectory was 2.1 mm, while the maximum linear deviation was 3.75 mm. Conclusion: When compared to freehand scaphoid guide wire insertion, our targeting device provides similar accuracy while significantly reducing intraoperative radiation exposure and procedure time.

Electromagnetic navigation-guided versus computed tomography-guided percutaneous localization of small lung nodules before uniportal video-assisted thoracoscopic surgery: a propensity score-matched analysis.

An optimal method for preoperative localization of small lung nodules is yet to be established, and there are few comparative studies in the literature. In the present study, we aimed to compare electromagnetic navigation-guided and computed tomography (CT)-guided methods of percutaneous transthoracic localization. The clinical, radiographic, surgical and pathological data of patients who underwent electromagnetic navigation-guided localization (EMNGL) and CT-guided localization (CTGL) before uniportal video-assisted thoracic surgery (VATS) were reviewed. Propensity score matching analysis was performed to compare the localization and surgical results. After matching, 25 EMNGL and 50 CTGL patients were included in the analysis. In the CTGL group, pulmonary haemorrhage and pneumothorax were noted in 56% and 34% of patients, respectively, on postprocedural CT scans. Successful localization was achieved in 96% and 100% of patients in the EMNGL and CTGL groups, respectively (P = 0.333). The median time in the operation room was significantly shorter in the CTGL group {142.5 [interquartile range (IQR) 123.8-175.0] vs 205.0 [IQR 177.5-290.0] min, P < 0.001}. In contrast, EMNGL significantly decreased the total time [205.0 (IQR 177.5-290.0) vs 324.0 (IQR 228.3-374.0) min, P = 0.002]. The median duration of chest drainage was 1 day shorter in the EMNGL group [2.0 (IQR 1.5-2.5) vs 3.0 (IQR 2.0-3.0), P = 0.002]; the surgical complication rates were comparable between the 2 groups. The localization and surgical results were similar between the EMNGL and CTGL groups. EMNGL is comparable to conventional CTGL with respect to preoperative localization of small lung nodules before uniportal VATS.

Analysis of the position of EndoAnchor implants in therapeutic use during endovascular aneurysm repair

ObjectiveThe aim of this study was to analyze the penetration depth, angles, distribution, and location of deployment of individual EndoAnchor (Medtronic Vascular, Santa Rosa, Calif) implants. MethodsEighty-six primary and revision arm patients (procedural success, 53; persistent type IA endoleak, 33) treated for type IA endoleaks with a total of 580 EndoAnchor implants from a subset of the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) were included in this study. Procedural success was defined as the absence of a type IA endoleak on the first postprocedural computed tomography scan after the EndoAnchor implantation procedure. Endograft malapposition along the circumference was assessed at the first postoperative computed tomography scans and expressed as clock-face range and width in degrees and normalized such that the center was translated to 0 degrees. The position and penetration of each EndoAnchor implant were measured as the clock-face orientation. EndoAnchor implant penetration into the aortic wall was categorized as follows: good penetration, ≥2 mm; borderline penetration, <2 mm or ≥2-mm gap between the endograft and aortic wall; or no penetration. The orthogonal and longitudinal angles between the EndoAnchor implant and the interface plane of the aortic wall were determined. Location of deployment was investigated for each EndoAnchor implant and classified as maldeployed when it was above the fabric or in a gap >2 mm between the endograft and aortic wall due to >2-mm thrombus or positioning of the EndoAnchor implant below the aortic neck. ResultsA total of 170 (29%) EndoAnchor implants had maldeployment and were therefore beyond recommended use and not useful. After EndoAnchor implantation, the procedural success and persistent type IA endoleak groups had 3 (1%) and 4 (2%) EndoAnchor implants positioned above the fabric as well as 60 (18%) and 103 (42%) placed in a gap >2 mm, respectively. The amount of EndoAnchor implants with good, borderline, and no penetration was significantly different between both groups (success vs type IA endoleak) after exclusion of maldeployed EndoAnchor implants (235 [87.4%], 14 [5.2%], and 20 [7.4%] vs 97 [68.8%], 18 [12.8%], and 26 [18.4%], respectively; P < .001). Good penetration EndoAnchor implants were more closely aligned with a 90-degree orthogonal angle than the borderline penetration and nonpenetrating EndoAnchor implants. The longitudinal angle was more distributed, which was observed through all three penetration groups. ConclusionsIn this subcohort of ANCHOR patients, almost 30% of the EndoAnchor implants had maldeployment, which may be prevented by careful preoperative planning and measured intraoperative deployment. If endoleaks are due to >2-mm gaps, EndoAnchor implants alone may not provide the intended sealing, and additional devices should be considered.

A Cadaveric Study on the Accuracy of an Individualized Guiding Template to Assist Scaphoid Fixation Using Computed Tomography and 3-Dimensional Printing

The aim of this study was to evaluate the feasibility and accuracy of scaphoid screw guidewire placement using a computer-assisted-designed, and 3-dimensional-printed, surgicalguiding template in cadaver wrists. Computed tomography (CT) scans of 12 fresh-frozen cadaver wrists were performed and the data imported into a surgical planning system. A 3-dimensional skin surface template block with a guiding hole was generated from the CT data to allow a screw guidewire to be placed in thecentral third of the scaphoid. This 3-dimensional model was printed and then put back onto thewrist. A screw guidewire was inserted through the palmar guide hole into the intact scaphoid and then a postprocedure CT scan was obtained. These postprocedure data were introduced into the surgical planning system. Angular and linear deviation between the preprocedural simulation and the image of the guidewire was measured in the system to assess accuracy. Mean angular deviation was 3.85° ± 1.32° (range, 1.56°-5.35°) and linear deviations of the 12 specimens were less than 1.1 mm. No specimen required a repeat drilling to the scaphoid. All the screw guidewires were considered to be centrally placed in the scaphoid based on our criterion of central placement of the scaphoid screw. The use of a computer-assisted 3-dimensional-printed surgical guide template to assist screw guidewire placement into an intact scaphoid, mimicking a nondisplaced scaphoid fracture, showed acceptable accuracy in cadaver wrists. Our technique may provide a simple and effective method for the guidance ofscrew guidewire insertion in a nondisplaced scaphoid fracture surgery.

P.104 Peri-cavity atrophy after minimally invasive evacuation of intracerebral hemorrhage

Background: Intracerebral hemorrhage (ICH) remains a significant cause of morbidity and mortality. While traditional surgical techniques have shown marginal clinical benefit of ICH evacuation, minimally invasive techniques have shown some promise. Endoscopic evacuation of the hemorrhage may reduce the peri-hematoma edema and subsequent atrophy around the hemorrhage cavity. This study aims to quantify the changes in cavity volume following hematoma evacuation. Methods: Patients from the INVEST registry of minimally invasive ICH evacuation were included retrospectively if follow-up computed tomography (CT) scans were available for analysis. Hematoma cavity volumes were calculated from the immediate post-procedural and three-month follow-up CT scans using the Analyze Pro software. Results: Twenty patients had follow-up CT scans at a mean time of 93 days from hematoma evacuation. The average cavity size at follow-up was 11938.12 mm3 (SD: 6996.49). The change in cavity size compared to the prior CT was 6396.74 mm3 (median 2542; range: -1030-27543; SD: 8472.45). This represented mean growth in cavity volume of 54%. Conclusions: This study provides preliminary data describing increase in cavity size after endoscopic minimally invasive evacuation of ICH. Comparison to atrophy in conservatively-managed patients is a further planned avenue of research.

Systemic air embolism after percutaneous computed tomography-guided lung biopsy due to a kink in the coaxial biopsy system: a case report

BackgroundSystemic air embolism is a rare but potentially life-threatening complication of percutaneous computed tomography (CT)-guided lung biopsy. The incidence might be underestimated because of failure to diagnose this adverse event in asymptomatic patients; early recognition is difficult.Case presentationWe report the case of a 73-year-old man with systemic air embolism, a complication of percutaneous CT-guided lung biopsy, due to a kink in the coaxial biopsy system. Serial post-procedure CT scans demonstrated the causal relationship.ConclusionsSequential post-biopsy CT scans demonstrated a causal relationship between this systemic air embolism and percutaneous biopsy, and allowed the radiologist to track the course of the emboli and their resolution. Awareness of air entry via the introducer needle and an early post-biopsy CT scan are crucial for early detection of systemic air embolism. If air embolism occurs in an asymptomatic patient, we recommend performing a delayed chest CT scan to follow the air’s course.

Retrospective analysis of technical success rate and procedure-related complications of 867 percutaneous CT-guided needle biopsies of lung lesions

To investigate the technical success rate and procedure-related complications of computed tomography (CT)-guided needle biopsy of lung lesions and to identify the factors that are correlated with the occurrence of procedure-related complications. This was a single- institution retrospective study of 867 consecutive CT-guided needle biopsies of lung lesions performed on 772 patients in a tertiary cancer centre. The technical success rate and complications were correlated with patient, lung lesion, and procedure-related variables. The technical success rate was 87.2% and the mortality rate was 0.12%. Of the 867 total biopsies 25.7% were associated with pneumothorax, and 6.5% required chest tube drainage. The haemothorax rate was 1.8%. There was positive correlation between the development of pneumothorax and smaller lesion diameter (p<0.001), longer transparenchymal distance (p<0.001), and prone position (p=0.027). There was positive correlation between the need for chest tube placement and longer transparenchymal distance (p=0.007) and smaller lesion diameter (p=0.018). Lesions in the left lower lobe had the lowest rates of pneumothorax (p=0.008) and chest tube drainage (p=0.018). Patients whose pneumothoraces were diagnosed on the follow-up chest X-ray, but not on the immediate post-procedural CT scan had significantly higher requirement for chest tube drainage (p=0.039). CT-guided lung biopsy has a high rate of technical success and a low rate of major complications. The present study has revealed several variables that can be used to identify high-risk procedures. A post-procedural chest X-ray within hours after the procedure is highly recommended to identify high-risk patients who require chest tube placement.