Tool For Surgical Planning Research Articles

Time Recommendation and Alternative Parameters for Severe Maxillofacial Trauma Reconstruction

Background: Severe maxillofacial trauma often associated with other injuries, therefore the delay of reconstruction often occur until the patients are stable. Early reconstruction results a better facial function and appearances. Aim: The aim of this study to give the recommendation and alternative parameters for severe maxillofacial trauma reconstruction. Methods: The method of this study is adult patients with bimaxillary and bilateral maxillofacial trauma were eligible for this study, while pregnant women were excluded. Nine patients with maxillofacial trauma were involved in this study and we measured 15 facial anthropometric and 41 lateral cephalometricon 7, 14, 21 days compared to 3 months post-reconstruction. Results: The result of this study showed reconstruction can be planned 14 days after trauma for lower jaw fracture and 21 days after bimaxillary fracture. Lateral cephalometry was a reliable method to measure facial edema following surgery which combined facial anthropometry with lateral cephalometry using parameters that are not affected by edema. This can be applied as an additional guiding tool in surgical planning for maxillofacial trauma patients especially those with bimaxillary and bilateral fractures. Conclusion: Combination of anthropometric and cephalometric parameters which are not affected by edema can be applied as an additional guiding tool in surgical planning for maxillofacial trauma patients.

A Patient-Specific Mixed-Reality Visualization Tool for Thoracic Surgical Planning

Identifying small lung lesions during minimally invasive thoracic surgery can be challenging. We describe 3-dimensional mixed-reality visualization technology that may facilitate noninvasive nodule localization. A software application and medical image processing pipeline were developed for the Microsoft HoloLens to incorporate patient-specific data and provide a mixed-reality tool to explore and manipulate chest anatomy with a custom-designed user interface featuring gesture and voice recognition. A needs assessment between engineering and clinical disciplines identified the potential utility of mixed-reality technology in facilitating safe and effective resection of small lung nodules. Through an iterative process, we developed a prototype employing a wearable headset that allows the user to (1) view a patient's original preoperative imaging; (2) manipulate a 3-dimensional rendering of that patient's chest anatomy including the bronchial, osseus, and vascular structures; and (3) simulate lung deflation and surgical instrument placement. Mixed-reality visualization during surgical planning may facilitate accurate and rapid identification of small lung lesions during minimally invasive surgeries and reduce the need for additional invasive preoperative localization procedures.

Preoperative functional MRI use in neurooncology patients: a clinician survey.

Functional MRI (fMRI) is increasingly being investigated for use in neurosurgical patient care. In the current study, the authors characterize the clinical use of fMRI by surveying neurosurgeons' use of and attitudes toward fMRI as a surgical planning tool in neurooncology patients. A survey was developed to inquire about clinicians' use of and experiences with preoperative fMRI in the neurooncology patient population, including example case images. The survey was distributed to all neurosurgical departments with a residency program in the US. After excluding incomplete surveys and responders that do not use fMRI (n = 11), 50 complete responses were included in the final analysis. Responders were predominantly from academic programs (88%), with 20 years or more in practice (40%), with a main area of practice in neurooncology (48%) and treating an adult population (90%). All 50 responders currently use fMRI in neurooncology patients, mostly for low- (94%) and high-grade glioma (82%). The leading decision factors for ordering fMRI were location of mass in dominant hemisphere, location in a functional area, motor symptoms, and aphasia. Across 10 cases, language fMRI yielded the highest interrater reliability agreement (Fleiss' kappa 0.437). The most common reasons for ordering fMRI were to identify language laterality, plan extent of resection, and discuss neurological risks with patients. Clinicians reported that fMRI results were not obtained when ordered a median 10% of the time and were suboptimal a median 27% of the time. Of responders, 70% reported that they had ever resected an fMRI-positive functional site, of whom 77% did so because the site was "cleared" by cortical stimulation. Responders reported disagreement between fMRI and awake surgery 30% of the time. Overall, 98% of responders reported that if results of fMRI and intraoperative mapping disagreed, they would rely on intraoperative mapping. Although fMRI is increasingly being adopted as a practical preoperative planning tool for brain tumor resection, there remains a substantial degree of discrepancy with regard to its current use and presumed utility. There is a need for further research to evaluate the use of preoperative fMRI in neurooncology patients. As fMRI continues to gain prominence, it will be important for clinicians to collectively share best practices and develop guidelines for the use of fMRI in the preoperative planning phase of brain tumor patients.

Virtual reality technology for teaching neurosurgery of skull base tumor

BackgroundNeurosurgery represents one of the most challenging and delicate of any surgical procedure. Skull base tumors in particular oftentimes present as a very technically difficult procedures in the setting of neurosurgical teaching. Virtual reality technology is one of the most promising surgical planning tools. It can perform fast three-dimensional (3D) reconstruction of computed tomography (CT), magnetic resonance imaging (MRI) and other imaging data sets under conditions of virtual reality (VR). Surgical simulation can more intuitively understand the anatomical relationship of the surgical area in significantly greater detail.MethodsThirty clinical undergraduates from the class of 2016 were randomly divided into two groups: the traditional teaching group and the virtual reality teaching group. After the study concluded, the teaching effectiveness was evaluated by combining basic theoretical knowledge, case analysis and questionnaire survey methods.ResultsComparative analysis between both groups showed the response effect of the virtual reality teaching group was better than that of the traditional teaching group (P < 0.05). There was also no difference between both groups in terms of the design of the surgical approach and the listing of surgical matters that required attention (P > 0.05).The results of theoretical knowledge assessment between both groups showed that the scores of basic theory, location, adjacent structure, clinical manifestation, diagnosis and analysis, surgical methods and total scores in the VR group exceeded those in the traditional teaching group (P < 0.05).ConclusionsThis study showed that VR technology might improve neurosurgical skull base teaching quality, which should be promoted in the teaching of clinical subjects.

Diagnostic Application of Fractal Dimension Analysis of Bone Invasion in Oral Malignancy—A Preliminary Retrospective Study

Introduction Fractal dimension (FD) analysis gives a numerical measure of the degree of boundary irregularity or surface roughness of an object and is based on quantitative analysis of features in an image. It quantifies the trabecular pattern of bone by analyzing the trabecular bone and bone marrow detecting the early changes in alveolar bone mineral content. The aim of this study is to assess the alveolar bone density by FD analysis in digital orthopantomograms (OPGs) showing bony erosion. Materials and Methods The OPGs of 10 patients from the archives of Department of Oral Medicine and Radiology were included in this retrospective study. The radiographs were selected based on set inclusion and exclusion criteria. FD analysis through box counting (using ImageJ software) was applied to the digital radiographs to establish a noninvasive evaluation of bone structure. The FD values obtained were recorded. Results The FD values were recorded and the data were analyzed. FD values showed statistical significance with p &lt;0.05. Conclusion With the number of samples analyzed and the results obtained, it can be concluded that FD analysis is an innovative method which can be used for early diagnosis of bony invasion in oral cancer. It can serve as a guide to dental surgeons in identifying the extent of bony invasion and can help in determining the margins of surgical resection of oral malignancy. This will prove to be a useful tool in surgical planning of oral malignancy.

Development and Proof-of-Concept Study of a Novel Intraoperative Surgical Planning Tool for Robotic Arm-Assisted Total Knee Arthroplasty

Background: Intraoperative surgical planning tools (ISPTs) used in current-generation robotic arm-assisted total knee arthroplasty (RTKA) systems (such as Navio® and MAKO®) involve employment of postoperative passive joint balancing. This results in improper ligament tension, which may negatively impact joint stability, which, in turn, may adversely affect patient function after TKA. Methods: A simulation-enhanced ISPT (SEISPT) that provides insights relating to postoperative active joint mechanics was developed. This involved four steps: 1) validation of a multi-body musculoskeletal model; 2) optimization of the validated model; 3) use of the validated and optimized model to derive knee performance equations (KPEs), which are equations that relate implant component characteristics to implant component biomechanical responses; and 4) optimization of the KPEs with respect to these responses. In a proof-of-concept study, KPEs that involved two com- ponent biomechanical responses that have been shown to strongly correlate with poor proprioception (a common patient complaint post-TKA) were used to calculate optimal positions and orientations of the femoral and tibial components in the TKA design implanted in one subject (as reported in a publicly-available dataset). Results: The differences between the calculated implant positions and orientations and the corresponding achieved values for the implant components in the subject were not similar to component position and orientation errors reported in biomechanical literature studies involving Navio® and MAKO®. Also, we indicate how SEISPT could be incorporated into the surgical workflow of Navio® with minimal disruption and increase in cost. Conclusion: SEISPT is a plausible alternative to current-gen- eration ISPTs.

Preoperative SPECT imaging as a tool for surgical planning in patients with axial neck and back pain.

Hybrid SPECT with CT imaging has been used to help elucidate pain generators in patients with axial neck and back pain, identifying potential sites for treatment. Few studies have examined its role in spine surgery and most literature focuses on its use postoperatively. The authors describe the largest series to date of patients with symptomatic spondylosis who underwent preoperative SPECT imaging for surgical planning. A retrospective medical and imaging record review was conducted to identify patients who underwent SPECT or SPECT/CT studies between January 2014 and May 2018. Patients who underwent spine surgical intervention for spondylosis with primary symptoms of axial neck or back pain and who had evidence of hypermetabolic foci on spinal SPECT imaging were included. Only those patients who subsequently underwent surgery on a spinal level associated with increased radiotracer uptake were included in the analysis. Patient baseline and demographic information, and data pertaining to SPECT imaging, surgical planning, and postoperative care were collected and analyzed. A total of 23 patients with an average age at surgery of 60.0 ± 11.0 years were included. Fifteen patients (65.2%) were male. A total of 53 spinal levels were treated, with an average of 2.30 levels treated per patient. All patients underwent fusion surgery, either lumbar (n = 14), with interbody fusion most commonly used (64.2%); or cervical (n = 9), with anterior cervical discectomy and fusion (66.6%) being the most common. The average length of hospital stay was 3.45 ± 2.32 days. One patient developed a wound infection postoperatively, requiring readmission. At the 3-month follow-up, 18 patients (78.3%) reported clinical improvement in pain. Eleven patients (47.8%) reported complete symptom resolution at the 6-month follow-up. At 1 year postoperatively, 19 patients (82.6%) reported significant relief of their symptoms following surgery. This is the largest series to date describing patients with axial neck and back pain who underwent preoperative SPECT imaging and subsequent surgical intervention on the affected spinal levels. The results demonstrate that SPECT imaging may be a useful adjunct to guide surgical planning, resulting in substantial clinical improvement following surgery.

Biomechanical profile of refractive surgery procedures

AbstractThe impact of corneal biomechanics continues to be increasingly recognized as an integral part of refractive surgery outcomes. Corneal biomechanical properties are of major importance in laser refractive surgery and must be taken into consideration to reduce the risk for iatrogenic ectasia. Some in vivo corneal biomechanical alterations are possible to quantify with ORA and Corvist ST but are difficult to interpret and use in clinical practice due to their dependence of IOP, CCT, refractive status, time from surgery and age. Development and refinement are needed if ORA and Corvis ST should be implemented in a screening procedure of the biomechanical strength before refractive surgery.Flap‐creation technique plays a major role in changing the biomechanical stability of the cornea. Nevertheless several studies suggest that the type of procedure is not as important as the native charac‐teristics of the patient’s cornea in determining the risk for ectasia. Although we may have reached a plateau of technological improvement in excimer laser tissue ablation, the introduction of small incision lenticule extraction (ReLEx SMILE), has changed the face of corneal refractive surgery in particular in its effect on corneal biomechanics. Mathematical analysis and finite‐element models suggest that SMILE may preserve corneal biomechanical properties better than LASIK. Furthermore, the current in vivo studies performed with ORA and Corvis ST indicate that SMILE is equal or superior to LASIK in terms of preservation of the postoperative biomechanical strength.However CH and CRF were reduced after refractive surgery but no differ‐ences were found between SMILE and flap‐based (FLEx and FS‐LASIK) refractive surgeries in the RCTs. Studies have demonstrated that in LASIK and PRK, the amount of refractive error corrected is related to the changes in corneal biomechanical properties. Considerable reduction in the corneal biomechanical properties observed even in ‘flap‐less’ procedures like PRK and SMILE,Brillouin microscopy provides safe and non contact method for measuring longitudinal elastic modulus of ocular tissues. It provides three‐dimensional resolution of the imaged tissue revealing spatial variations in mechanical properties. Its clinical usefulness has already been demonstrated in corneal diagnostic and treatment monitoring and may eventually be a valuable tool for surgical planning of refractive and therapeutic procedures.question both in vivo and ex vivo, and by mathematical or finite‐element models of the cornea

Surgical mapping of middle ear cholesteatoma with fusion of computed tomography and diffusion-weighted magnetic resonance images: Diagnostic performance and interobserver agreement

ObjectiveTo assess the diagnostic performance in detecting primary cholesteatoma at various anatomical subsites using Computed Tomography (CT), Diffusion-weighted Magnetic Resonance Imaging (DWMRI) and Fusion of CT and DWMRI (Fusion CT-MRI) images. Study designA retrospective study of 22 children identified from a prospective database of surgically treated cholesteatoma cases over a five year period. All cases underwent pre-operative CT, non-echo planar DWMRI and Fusion CT-DWMRI, and with clearly documented surgical findings. For each imaging modality, two radiologists scored for the presence or absence of cholesteatoma with confidence levels at different anatomical subsites. The radiologists were blinded to the surgical findings to which their findings were compared. SettingLarge Teaching Hospital in London. Patients22 children with cholesteatoma confirmed surgically. InterventionCT, DWMRI imaging and fusion CT-MRI. Main outcome measureDiagnostic performance of subsite localisation of cholesteatoma by CT, DWMRI and fusion CT-MRI imaging with intra-operative findings. ResultsTwenty-two patients were included (12 women and 10 men). The median age of patients was 11 years. When considering all subsites combined, the result for all imaging methods suggested ‘good’ agreement between both observers. When all subsites were examined together, all methods had relatively high sensitivity values (87% for CT vs 84% for DWMRI vs 85% for fusion CT-DWMRI). Specificity was highest with fusion CT-DWMRI (46% for CT vs 76% for DWMRI vs 97% for fusion CT-DWMRI), as was accuracy (66% for CT vs 80% for DWMRI vs 91% for fusion). ConclusionsOur study has demonstrated that fusion CT-DWMRI is superior to DWMRI or CT separately in localizing cholesteatoma at various middle ear cleft subsites and bony relations, making it a valuable tool for surgical planning.

3D Printing in Gynecologic Surgery – an Innovative Tool for Surgical Planning

Study Objective To evaluate the impact of 3-dimensional (3D) digital and printed models on minimally invasive gynecologic surgeons’ operative plan, outcomes, and experience. Design Prospective, cross-sectional, repeated measures design. Setting Pre-, intra-, and post-operative minimally invasive gynecologic surgery. Patients or Participants Minimally Invasive Gynecology (MIG) surgeons (n=6) at The Ottawa Hospital (TOH) and their respective surgical cases (n=50). Interventions Using our team's 3D printing protocol, patient-specific 3D digital and printed models are produced from cross-sectional MR images. Surgeons complete a pre-operative questionnaire before and after viewing the models. They are given the opportunity to consult the models intra-operatively, and, finally, complete a post-operative questionnaire. Chi-square test of independences, Mann-Whitney U, and dependent T-tests will be used to evaluate significant differences between variables related to surgical plan before and after viewing models. Descriptive statistics will be used to evaluate surgeon experience. Measurements and Main Results Two cases have been completed to date. The first was a proof of concept to establish our 3D printing and study protocols. In this case, a 3D model of a multifibroid uterus was printed for myomectomy planning in a 42-year-old G0P0 with bulk symptoms. In the second case, a 3D model was printed to plan for myomectomy in a 45-year-old G5P1 with future fertility goals. Viewing the 3D digital and printed model affected the surgeons’: planned hemostatic techniques, perceived surgical complexity, allocated operative time, anticipated risk of complications, confidence in surgical plan, and positively impacted their surgical experience. Conclusion Patient-specific 3D models increase understanding of complex anatomy in gynecologic surgery, optimizing pre-operative planning, intra-operative performance, surgeon experience, and patient outcomes.

Machine learning in cardiovascular flows modeling: Predicting arterial blood pressure from non-invasive 4D flow MRI data using physics-informed neural networks

Advances in computational science offer a principled pipeline for predictive modeling of cardiovascular flows and aspire to provide a valuable tool for monitoring, diagnostics and surgical planning. Such models can be nowadays deployed on large patient-specific topologies of systemic arterial networks and return detailed predictions on flow patterns, wall shear stresses, and pulse wave propagation. However, their success heavily relies on tedious pre-processing and calibration procedures that typically induce a significant computational cost, thus hampering their clinical applicability. In this work we put forth a machine learning framework that enables the seamless synthesis of non-invasive in-vivo measurement techniques and computational flow dynamics models derived from first physical principles. We illustrate this new paradigm by showing how one-dimensional models of pulsatile flow can be used to constrain the output of deep neural networks such that their predictions satisfy the conservation of mass and momentum principles. Once trained on noisy and scattered clinical data of flow and wall displacement, these networks can return physically consistent predictions for velocity, pressure and wall displacement pulse wave propagation, all without the need to employ conventional simulators. A simple post-processing of these outputs can also provide a relatively cheap and effective way for estimating Windkessel model parameters that are required for the calibration of traditional computational models. The effectiveness of the proposed techniques is demonstrated through a series of prototype benchmarks, as well as a realistic clinical case involving in-vivo measurements near the aorta/carotid bifurcation of a healthy human subject.

AAFD: Conventional Radiographs are not Enough! I Need the Third Dimension

There is an increasing amount of literature suggesting that 3-dimensional (3D) weight-bearing computed tomography (WBCT) imaging overcomes the inherent limits of traditional bidimensional imaging in foot and ankle surgery. This seems to have a significant impact on the study and on the clinical management of adult acquired flatfooot deformity (AAFD) that by definition is a 3D complex deformity. In this study, we reviewed the recent literature about the use of WBCT in AAFD, starting from a critical analysis about the biases related to conventional radiography and to non-standing CT. Then, we focused on the effects of load on the 3D architecture of the foot and ankle in AAFD. Finally, we discussed the benefits and future perspectives for the use of WBCT in the management of this condition and as a surgical planning tool as well. Level of Evidence: Diagnostic Level V, expert opinion. See Instructions for Authors for a complete description of levels of evidence.

Preoperative Single Photon Emission Computed Tomography Imaging as a Tool for Surgical Planning in Patients With Axial Neck and Back Pain

Abstract INTRODUCTION Single Photon Emission Computed Tomography (SPECT) imaging has recently been employed to identify pain generators in patients with axial neck and back pain, indicating potential sites of degeneration. We describe the largest series to date of patients with axial neck or back who underwent preoperative SPECT imaging for surgical planning. METHODS A retrospective medical and imaging record review was conducted to identify patients who underwent SPECT or SPECT/CT studies between January 2014 and May 2018. Surgical criteria included symptoms of intractable back or neck pain and evidence of degenerative pathology on SPECT imaging. Only those patients who subsequently underwent surgery on a spinal level associated with increased radiotracer uptake were included in the analysis. Patient baseline and demographic information, and data pertaining to SPECT imaging, surgical planning, and postoperative care was collected and analyzed. RESULTS A total of 23 patients with an average age at surgery of 60.0+/−11.0 yr were included. About 15 patients (65%) were male. A total of 53 spinal levels were treated, with an average of 2.30 levels treated per patient. All patients underwent fusion surgery, either lumbar (14) with interbody fusion most commonly employed (64.2%) or cervical (9) with anterior cervical discectomy and fusion (66.6%) most common. Average LOS was 3.45+/−2.32 d. One patient developed a wound infection postoperatively, requiring readmission. At 3-mo follow-up, 18 patients (78.3%) reported clinical improvement in pain. About 11 patients (47.8%) reported complete symptom resolution at 6-mo follow-up. At 1 yr postoperatively, 19 patients (82.6%) reported some relief of their symptoms following surgery. CONCLUSION This is the largest series to date describing patients with axial neck and back pain who underwent preoperative SPECT imaging and subsequent surgical intervention on the affected spinal levels. Our results demonstrate that SPECT imaging may be a useful adjunct to guide surgical planning, resulting in substantial clinical improvement following surgery.

A perfusion territory shift attributable solely to the secondary collaterals in moyamoya patients: a potential risk factor for preoperative hemorrhagic stroke revealed by t-ASL and 3D-TOF-MRA.

The authors conducted a study to noninvasively and nonradioactively reveal moyamoya disease (MMD) intracerebral perfusion and perfusion territory supplied by the unilateral internal carotid artery (ICA) and external carotid artery (ECA) and bilateral vertebral arteries (VAs) before surgery and to further identify risk factors for preoperative hemorrhage in adult MMD. Forty-three consecutive adult patients with bilateral MMD underwent unenhanced T1-weighted MRI, territorial arterial spin labeling (t-ASL), and unenhanced 3D time-of-flight MRA (3D-TOF-MRA). Clinical factors, including age, sex, hypertension, diabetes mellitus, hyperlipidemia, current smoking status, and history of taking aspirin, were gathered and stratified. Univariate logistic regression analyses were used to examine the relationship between various risk factors and the occurrence of preoperative hemorrhage. Stepwise multivariate logistic regression analyses were used to determine independent risk factors of preoperative hemorrhage in MMD. Among the 86 MMD hemispheres, t-ASL revealed 137 perfusion territory shifts in 79 hemispheres. Five distinct categories of perfusion territory shifts were observed on t-ASL maps. The subtypes of perfusion territory shift on t-ASL maps were further subdivided into 2 different categories, group A and group B, in combination with findings on 3D-TOF-MRA. A perfusion territory shift attributable solely to the secondary collaterals was a potential independent risk factor for preoperative hemorrhage (p = 0.026; 95% CI 1.201-18.615; OR 4.729). After eliminating the influence of the secondary collaterals, the primary collaterals had no significant effect on the risk of preoperative hemorrhage (p = 0.182). t-ASL could reveal comprehensive MMD cerebral blood perfusion and the vivid perfusion territory shifts fed by the unilateral ICA and ECA and bilateral VAs in a noninvasive, straightforward, nonradioactive, and nonenhanced manner. 3D-TOF-MRA could subdivide t-ASL perfusion territory shifts according to their shunt arteries. A perfusion territory shift attributable to the secondary collaterals is a potential independent risk factor for preoperative hemorrhage in MMD patients. A perfusion territory shift fed by the primary collaterals may not have a strong effect on preoperative hemorrhage in MMD patients. These findings make the combined modalities of t-ASL and 3D-TOF-MRA a feasible tool for MMD disease assessment, management, and surgical strategy planning.

Layered manufacturing for medical imaging data

Layered manufacturing techniques have been successfully employed to construct scanned objects from three-dimensional medical image data sets. The printed physical models are useful tools for anatomical exploration, surgical planning, teaching, and related medical applications. Before fabricating scanned objects, we have to first build watertight geometrical representations of the target objects from medical image data sets. Many algorithms had been developed to fulfill this duty. However, some of these methods require extra efforts to resolve ambiguity problems and to fix broken surfaces. Other methods cannot generate legitimate models for layered manufacturing. To alleviate these problems, this article presents a modeling procedure to efficiently create geometrical representations of objects from computerized tomography scan and magnetic resonance imaging data sets. The proposed procedure extracts the iso-surface of the target object from the input data set at the first step. Then it converts the iso-surface into a three-dimensional image and filters this three-dimensional image using morphological operators to remove dangling parts and noises. At the next step, a distance field is computed in the three-dimensional image space to approximate the surface of the target object. Then the proposed procedure smooths the distance field to soothe sharp corners and edges of the target object. Finally, a boundary representation is built from the distance field to model the target object. Compared with conventional modeling techniques, the proposed method possesses the following advantages: (1) it reduces human efforts involved in the geometrical modeling process. (2) It can construct both solid and hollow models for the target object, and wall thickness of the hollow models is adjustable. (3) The resultant boundary representation guarantees to form a watertight solid geometry, which is printable using three-dimensional printers. (4) The proposed procedure allows users to tune the precision of the geometrical model to compromise with the available computational resources.

Comprehensive Review of 3D Segmentation Software Tools for MRI Usable for Pelvic Surgery Planning.

Patient-specific 3D modeling is the first step towards image-guided surgery, the actual revolution in surgical care. Pediatric and adolescent patients with rare tumors and malformations should highly benefit from these latest technological innovations, allowing personalized tailored surgery. This study focused on the pelvic region, located at the crossroads of the urinary, digestive, and genital channels with important vascular and nervous structures. The aim of this study was to evaluate the performances of different software tools to obtain patient-specific 3D models, through segmentation of magnetic resonance images (MRI), the reference for pediatric pelvis examination. Twelve software tools freely available on the Internet and two commercial software tools were evaluated using T2-w MRI and diffusion-weighted MRI images. The software tools were rated according to eight criteria, evaluated by three different users: automatization degree, segmentation time, usability, 3D visualization, presence of image registration tools, tractography tools, supported OS, and potential extension (i.e., plugins). A ranking of software tools for 3D modeling of MRI medical images, according to the set of predefined criteria, was given. This ranking allowed us to elaborate guidelines for the choice of software tools for pelvic surgical planning in pediatric patients. The best-ranked software tools were Myrian Studio, ITK-SNAP, and 3D Slicer, the latter being especially appropriate if nerve fibers should be included in the 3D patient model. To conclude,this study proposed a comprehensive review of software tools for 3D modeling of the pelvis according to a set of eight criteria and delivered specific conclusions for pediatric and adolescent patients that can be directly applied to clinical practice.

Evaluation of Diagnostic Accuracy of Anal Fistula by 360° Endoanal Ultrasound

Introduction: 360° endoanal ultrasound (EAUS) has become an effective imaging tool to diagnose anal fistulas for last three decades.&#x0D; Objectives: To assess the diagnostic accuracy of 360° endoanal ultrasound imaging comparing pre and peroperative diagnosis in anal fistulas.&#x0D; Methods: Between Jauary 2015 and June 2018, 240 patients with clinical anal fistula underwent endoanal sonographic assessment using a 360° endoanal transducer (7–15 MHz The sonographic findings, including the fistulas and other inflammatory lesions, were correlated with surgical results. The types of fistulas on endoanal sonography based on classification of Park and the internal opening of the fistula, both pre and peroperative, were compared to those of other studies.&#x0D; Results: The 240 patients studied included 165 male and 75 female patients. Endoanal sonography was able to show and track hypoechoic lesions, their locations, and internal openings of the fistulas. Compared with surgical results, endoanal sonography had sensitivity of 94.6%, specificity of 100%, and accuracy of 94.1% for the diagnosis of perianal fistulas. Also, endoanal sonography had accuracy of 86.1% for determining fistula types based on the Parks classification and 92.8% for identifying internal openings of the fistulas.&#x0D; Conclusions: Endoanal ultrasound is an accurate and noninvasive imaging modality for evaluation of fistulas. It is a very useful tool for preoperative management and surgical planning by providing precise and detailed information on fistulas.&#x0D; J Shaheed Suhrawardy Med Coll, December 2018, Vol.10(2); 66-69

Preoperative risk evaluation for pancreatic fistula after pancreaticoduodenectomy.

Pancreatic fistula remains common, with limited ability to risk stratify patients preoperatively. The objective of this study was to identify risk factors for clinically-relevant postoperative pancreatic fistula (CR-POPF) that are routinely available in the preoperative setting. Preoperatively available variables for all pancreaticoduodenectomies from 2014-2017 were examined using a national clinical registry. The cohort was separated into risk factor identification and internal validation subgroups. Among 15 033 pancreaticoduodenectomies, the CR-POPF rate was 16.7%. CR-POPF was more likely in patients that were male (odds ratio [OR], 1.51), obese (body mass index [BMI] > 30, OR, 1.97), had minimal preoperative weight loss (OR, 1.25), had a nondilated pancreatic duct (OR, 1.81), did not have diabetes, (OR, 1.80), did not receive neoadjuvant therapy (OR, 1.78), had no evidence of biliary obstruction (OR, 1.18), or had nonadenocarcinoma pathology (OR, 1.96; all P < 0.01). Patients with three or fewer risk factors had a CR-POPF rate of 7.1%, while those with six or more risk factors had a CR-POPF rate of 26.3% (P < 0.001). Preoperative CR-POPF risk evaluation could be a useful tool in patient counseling and surgical planning, and risk may allow for more well-informed decisions regarding perioperative management, including enhanced recovery protocols and use of somatostatin analogs.

The use of rotational fluoroscopy and 3-D reconstruction in the diagnosis and surgical planning for complex cloacal malformations

IntroductionCloacal malformations, a confluence of the urinary tract, vagina and rectum into a single common channel, has a broad and complex anatomic spectrum requiring an imaging tool for visualization, measurement, and surgical planning for the reconstruction of these structures. We evaluated the role of 3-D fluoroscopy for this purpose, as it offers a combination of spatial correlation with precise anatomic measurements. MethodsWe examined our imaging protocol for patients with a cloacal malformation and report our experience with rotational fluoroscopy and 3-D reconstruction in 16 consecutive patients referred for cloacal reconstruction. The length of the common channel (CC), the length of the urethra from the bladder neck to the common channel, and the height (and existence or absence) of a vagina or vaginas were determinants of the surgical procedures used for the repair. ResultsWe performed 16 consecutive 3-D cloacagrams (age range 4 months to 9 years) using a new protocol (Figure 1) that provided the following data which helped with surgical planning: Gynecologic: 3 cases with a single vagina, 5 cases with a duplicated Mullerian system (3 of which were asymmetric) and 2 cases with high vaginas requiring vaginal replacement. Colorectal: Four had a high rectum requiring an abdominal approach, and 6 had a rectum reachable via a posterior sagittal approach. Urologic: Two ectopic ureters requiring reimplantation, 3 patients had vesicoureteral reflux (1 bilateral, 2 unilateral), 1 patient had no bladder, and 7 had a normal sized bladder. Common channel length and urethral length were demonstrated in all cases and used to decide between a total urogenital mobilization or a separation of vagina(s) from the common channel, urogenital separation. ConclusionThe 3-D cloacagram can help predict the surgical plan for urologic, gynecologic, and colorectal components of the cloacal repair. It can predict the CC length as well as the length of the urethra. It helps with predicting the need for vaginal replacement and whether an abdominal approach is needed for the rectum. Its effectiveness is based on the ability to adequately distend structures and see their distal most extent, an advantage over other modalities such as MRI. Added benefits (particularly from the 3D view) include a better spatial understanding of the defect and the diagnosis of concomitant urological abnormalities such as vesicoureteral reflux and ectopic ureters. Disadvantages to this procedure include the need for general anesthesia and a higher exposure to radiation. Level of evidence3.

Associations between clinical outcome and tractography based on navigated transcranial magnetic stimulation in patients with language-eloquent brain lesions.

Navigated transcranial magnetic stimulation (nTMS) in combination with diffusion tensor imaging fiber tracking (DTI FT) is increasingly used to locate subcortical language-related pathways. The aim of this study was to establish nTMS-based DTI FT for preoperative risk stratification by evaluating associations between lesion-to-tract distances (LTDs) and aphasia and by determining a cut-off LTD value to prevent surgery-related permanent aphasia. Fifty patients with left-hemispheric, language-eloquent brain tumors underwent preoperative nTMS language mapping and nTMS-based DTI FT, followed by tumor resection. nTMS-based DTI FT was performed with a predefined fractional anisotropy (FA) of 0.10, 0.15, 50% of the individual FA threshold (FAT), and 75% FAT (minimum fiber length [FL]: 100 mm). The arcuate fascicle (AF), superior longitudinal fascicle (SLF), inferior longitudinal fascicle (ILF), uncinate fascicle (UC), and frontooccipital fascicle (FoF) were identified in nTMS-based tractography, and minimum LTDs were measured between the lesion and the AF and between the lesion and the closest other subcortical language-related pathway (SLF, ILF, UC, or FoF). LTDs were then associated with the level of aphasia (no/transient or permanent surgery-related aphasia, according to follow-up examinations). A significant difference in LTDs was observed between patients with no or only surgery-related transient impairment and those who developed surgery-related permanent aphasia with regard to the AF (FA = 0.10, p = 0.0321; FA = 0.15, p = 0.0143; FA = 50% FAT, p = 0.0106) as well as the closest other subcortical language-related pathway (FA = 0.10, p = 0.0182; FA = 0.15, p = 0.0200; FA = 50% FAT, p = 0.0077). Patients with surgery-related permanent aphasia showed the lowest LTDs in relation to these tracts. Thus, LTDs of ≥ 8 mm (AF) and ≥ 11 mm (SLF, ILF, UC, or FoF) were determined as cut-off values for surgery-related permanent aphasia. nTMS-based DTI FT of subcortical language-related pathways seems suitable for risk stratification and prediction in patients suffering from language-eloquent brain tumors. Thus, the current role of nTMS-based DTI FT might be expanded, going beyond the level of being a mere tool for surgical planning and resection guidance.