Invasive Treatment Research Articles

EGS SO17 - Foreign body management - Time for improvement

Abstract Background The management of foreign bodies (FBs) in clinical practice presents significant challenges across various medical specialties. FBs can be ingested, inhaled, inserted, or result from trauma, necessitating a comprehensive understanding of their management to prevent complications. The prevalence of FB incidents varies by age, with children being particularly susceptible to ingestion and inhalation, while adults often encounter FBs through trauma or occupational hazards. Effective management strategies are crucial to minimize morbidity and mortality associated with FB incidents. Method This study retrospectively reviewed cases of FB management over eight years (2015-2023), encompassing various specialties including gastroenterology, upper gastrointestinal and colorectal surgery. Data were collected on patient demographics, type and location of FB, method of removal, complications, and outcomes. Imaging techniques, such as X-rays, CT scans, and endoscopic evaluations, were analysed for their efficacy in FB detection. Different removal techniques, including endoscopic, surgical, and non-invasive methods, were evaluated for success rates and associated complications. Results Of the 153 FB incidents,47% involved male patients and 53% involved female patients.The paediatric group accounted for 36% of incidents.Non-invasive management was successful in 62% of cases,while 37% required invasive procedures.Among invasive interventions,70% required operative intervention,10% endoscopic intervention and 20% other minimally invasive options.The time to intervention for invasive procedures varied with more than 50% taking place after 24 hours.For operative interventions,64% occurred over 24 hours after presentation,21% within less than 24 hours, and 14% within 12 hours.All endoscopic interventions were performed within 12 hours.Outcomes showed that 96% of cases were managed without further complications.There were no reported mortalities. Conclusion Effective management of FBs requires a timely and appropriate intervention strategy tailored to the patient’s age and the type of FB. Non-invasive methods successfully managed most cases, while invasive procedures were necessary for a significant proportion. Prompt intervention, particularly endoscopic and other minimally invasive techniques, was associated with favorable outcomes and minimal complications. No mortalities were reported, underscoring the efficacy of current management protocols. Further research is needed to optimize these protocols and improve outcomes across diverse patient populations.

HPB SO62 - Association of positive bile cultures and the incidence of pancreatic fistulas post pancreaticoduodenectomy[PD

Abstract Background Postoperative pancreatic fistula (POPF) remains a significant complication post pancreaticoduodenectomy (PD). Recent publications show no increased incidence of POPF due to positive bile cultures. A literature search on PubMed did not show any review on the relevance of specific cultures and their exact incidence of POPF. POPF is defined as Drain Amylase greater than three times its serum level on or after postoperative day 3. A relatively benign clinical course is grade A, moderately unwell patients requiring medical/minimal intervention (grade B), and critically ill patients with sepsis, requiring invasive intervention (grade C). Grade B + C is defined as CR-POPF. Method A retrospective single-centre analysis of all patients with pancreaticoduodenectomy between 2017 and 2021 was reviewed. The clinical data that were reviewed were age, gender, length of stay[LOS], tumour staging, mortality rates, Pancreatic duct[PD], Pre-op stenting, the documented incidence of POPF/CR-POPF, Intra-Operative Bile Cultures[IOBC] and antibiotic sensitivity. The primary outcome was POPF. Secondary outcomes were 90-day mortality, LOS, return to theatre, Postoperative haemorrhage (POPH), and organ-specific relevance of POPF. All data was analysed using SPSS IBM version 29. P< 0.05 was taken as clinically significant. Results 100 patients were included in the study. The mean age was 68.8 (SD-9.5). The M: F ratio was 54:46. The mean postoperative length of hospital stay was 19.38 days. 48 patients (48%) were diagnosed with a POPF, among which, 22 patients (47.8%) developed a CR-POPF. 57 patients had a positive IOBC. The incidence of POPF in patients with Positive IOBC was 43/57(75.43%) and that was 5/43(11.62%) of the patients with Negative IOBC (P < .0001).10% of patients had postoperative haemorrhage (POPH). 9% had 90-day mortality. All 9% of patients who had a return to theatre had POPF. Conclusion Univariate analysis and logistic regression demonstrated that a positive IOBC had a higher associated incidence of POPF who underwent PD, with Klebsiella being the most common and statistically significant[P<.005]. The most common antibiotic found to be sensitive was Gentamicin, which is 25 per cent and, in combination with Co-amoxiclav, was found to be sensitive in 21.8% of cases. However, this is a single-centre retrospective study with variable operative techniques for different patient groups. Further studies would be warranted before correlating any results to all populations of patients developing POPF post pancreaticoduodenectomy.

EGS SO24 - Endoscopic Vacuum Therapy for Oesophageal Perforation and Anastomotic Leaks

Abstract Background Oesophageal perforations and oesophago-gastric (OG) anastomotic leaks are challenging conditions, associated with significant morbidity and mortality. In recent years, endoscopic vacuum (EndoVac) therapy has emerged as a novel, alternative intervention for source control and to promote healing. Introduced to our unit in 2019, this cohort study presents our experience with EndoVac management of both post operative OG anastomotic leaks and primary oesophageal ruptures. Method Retrospective analysis of patient electronic records was conducted for all patients who received EndoVac management between the study period of October 2019 to June 2023. Pertinent outcome variables included length of vacuum therapy, number of changes, length of admission, in hospital and 90 day mortality rates. Results 37 patients were identified within the study period. The average age of this study cohort was 68 years with a mode ASA of III. The most common indication for EndoVac therapy was anastomotic leak (56%), followed by oesophageal perforation (31%). Defect resolution was achieved in 72% of patients. The median duration of treatment was 26 days (range 2-157), whilst the median number of changes was 7 (range 2-31). The overall in hospital complication (Clavien Dindo I-V) rate was 34%. The 90-day mortality rate was 22% whilst the morbidity rate was 13% in the form of anastomotic stricturing requiring serial dilatations. Conclusion EndoVac therapy is an effective minimally invasive treatment for post operative OG anastomotic leaks and oesophageal ruptures. With ongoing expansion in it’s use in our unit and throughout the UK, further work is required to assess the long-term outcomes and develop guidelines around its use in both oesophageal leaks and perorations.

Effective Ayurvedic Treatment of Pilonidal Sinus using Udumber Ksheer Sutra: A Case Study

ABSTRACT Pilonidal sinus, also known as “jeep bottom,” is common among people who sit a lot, such as cab drivers. It mostly affects men and young adults and is associated with thick hair. Surgical techniques are available for treatment, but the condition has a relatively high recurrence rate. The Kshara Sutra method described in the Sushruta Samhita offers a minimally invasive treatment option. Pilonidal disease is estimated to affect about 26 out of every 100,000 persons, with around 0.7% of people affected. This study focuses on the diagnosis and treatment of patients who have Naadi Vrana (Pilonidal Sinus) using Udumber Ksheer Sutra. The Kshara Sutra is a minimally invasive, cost-effective technique with a low recurrence rate for treating pilonidal sinus. Udumber Ksheer Sutra management has also proven to be beneficial as a curative therapy for the pilonidal sinus.

Endoscopic intermuscular dissection: insights from China on minimally invasive treatment for early rectal cancer

Endoscopic intermuscular dissection: insights from China on minimally invasive treatment for early rectal cancer

BN SO47 - Can Peroral Endoscopic Myotomy (POEM) be the new gold standard for Achalasia? – as it is safe and effective

Abstract Background Laparoscopic Heller’s cardiomyotomy is the gold standard for treatment of achalasia. POEM has emerged as a revolutionary minimal invasive procedure in the management of achalasia and related oesophageal motility disorders. POEM effectively utilises an endoscopic approach by creating a submucosal tunnel to perform a myotomy at the lower oesophageal sphincter (LES) , achieving symptomatic relief. Being firstly introduced in 2008, POEM offers an excellent alternative option to surgical intervention and conservative approaches. The aim of this study is to evaluate the clinical efficacy and safety of POEM since its introduction in our unit. Method POEM procedures performed in adult patients are recruited prospectively from May 2020 to January 2024 and data are collected using electronic trust records. Eckardt score (a commonly used scoring system to characterise severity of achalasia) is recorded before and after the procedure. A total of 46 patients are identified however three patients are excluded in this study due to unavailable clinical information. This study presents a cohort of patients with median age of 60 and an equal gender distribution. Results Out of 43 patients, 69.8% were treatment naïve and 30.2% had previous treatments. Mean Eckardt score pre-procedure was 8.2. The average length of hospital stay was 1.7 days and immediate post treatment complications were 6.9% (2.3% mucosotomy, 2.3% oesophageal leak, 2.3% infection). No mortality was recorded within 30 days post-procedure. A 93% clinical success rate (Eckardt score ≤3) was achieved in the initial follow-up period (three to six months) with a mean Eckardt score of 1.1. 41.9% of patients experienced reflux symptoms which require proton pump inhibitor use within four weeks post-procedure. 18.4% of patients had recurrent achalasia symptoms over their follow-up period. Conclusion The clinical success rate (Eckardt score ≤3) and recurrence rate post POEM in this study are comparable with the international cohort quoted in literature. Post POEM reflux rate is prevalent, which is a well-known complication. The substantial improvement in clinical outcomes, evidenced by the Eckardt score reduction and the low incidence of post-operative complications, underscores the procedure’s efficacy and safety. Overall, POEM represents a significant advancement in the treatment of oesophageal motility disorders, especially achalasia. This study presents POEM as a safer and less invasive treatment alternative compared to Heller’s cardiomyotomy.

GAMMA KNIFE AND QUALITY OF LIFE: A REVIEW ON THE USE OF RADIOSURGERY IN BRAIN TUMORS

INTRODUCTION: Considering the quality of life of patients with brain tumors, several treatment alternatives have been developed over time, aiming at a less invasive potential and providing a permanent functional capacity for the individual. In this regard, in recent decades there has been debate about radiosurgery for the treatment of brain tumors. OBJECTIVE: The objective of this study was to evaluate the feasibility of Gamma Knife radiosurgery, considering patient safety. METHODS: This article is characterized as an integrative literature review of an exploratory nature, in the PubMED and Cochrane databases, the search was restricted to observational studies and randomized clinical trials as primary data to contemplate the outcomes Quality of life, neurological preservation, recurrence, cerebral complications and overall survival. RESULTS: The analysis of the collected data demonstrated that, in general, radiosurgery by the Gamma Knife platform preserves quality of life in several cases, mainly in smaller benign brain tumors. The disease recurrence rate after 3 years of radiosurgery ranged from 20 to 40%, depending on the type of tumor and treatment, with the highest recurrence rate in grade III meningiomas and high-grade gliomas. The 5-year recurrence rate ranged from 60 to 80%, and was therefore higher than that of more invasive treatments. CONCLUSION: The qualitative synthesis of these data proves the efficacy of radiosurgery and may suggest to neurosurgeons the possibility of treating brain tumors in patients who are not eligible for conventional surgery or in patients with non-bulky tumors.

Insights Into Minimally Invasive Aesthetic Procedures- Defining Demographic Factors and Impact of the Treatment on Self Perception: A Propensity Matched Cross Sectional Study

Abstract Background The lion´s share of the research on facial aesthetic procedures focuses on visual results and patient satisfaction. Objectives To characterize treated and untreated potential patients and the identification of determinants that influence the decision making as well as the impact of such treatments on patients’ self-perception. Methods A cross-sectional propensity-score-matched study on minimally invasive aesthetic procedures was performed through a survey comprising elements regarding demographics, conduct towards minimally invasive facial plastic interventions as well as psychological well-being and social self-esteem domains of the validated Face-Q module. Results Complete data was collected from 598 participants. Among those, 88% (n=529) were female and 12% (n=69) were male. Forty-six percent (n=277) of the participants were below the age of 30, and 39% (n=233) percent were between 30 and 45 years of age. Of the 598 participants, 22% (n=134) participants had undergone a minimally invasive aesthetic procedure of botulinum toxin and/or hyaluronic acid injection and 78% (n=464) participants had never received any aesthetical treatment. Female gender, 30-45 years of age, self-employment and an income over 75000€ were significant predictors of undergoing minimally invasive aesthetic procedures. Among treated participants, the overall Face-Q score as well as the scores for the social-esteem and the psychological well-being domains improved significantly with the aesthetic treatment. Conclusions This study highlights the major role of healthcare providers in better informing patients and the positive impact of facial aesthetic treatments on patients’ appearance as well as on psychological wellbeing and self-esteem.

Abstract Su501: Feasibility and Implications of Electrocardiogram-based Prediction of Incessant Refractory Ventricular Fibrillation

Background: Refractory ventricular fibrillation (R-VF) patients, defined as requiring ≥ 3 shocks during resuscitation of OHCA, have relatively poor outcomes. Prior studies have predicted R-VF using the ECG, suggesting potential to guide early patient-specific treatment for R-VF. However, R-VF comprises multiple phenotypes with distinct defibrillation response profiles: Incessant VF (no shocks terminate VF), recurrent VF (all shocks terminate VF but VF recurs), or mixed VF (shocks variably terminate VF). These phenotypes may have distinct prognoses, and may also respond differently to R-VF treatments such as early antiarrhythmics, modified vasopressor dosing, alternative defibrillation strategies, or expedited invasive interventions. Early prediction of specific R-VF phenotype could potentially improve outcome through preemptive targeting of treatment to individual phenotype. Aim: We sought to predict incessant R-VF using machine learning analysis of the defibrillator ECG. Methods: We performed a retrospective study of adult VF OHCA treated by EMS from 2006–2019 in King County WA. We linked a clinical OHCA registry with defibrillator recordings to evaluate ROSC and survival to hospital discharge by VF type (non-refractory; or incessant, recurrent, or mixed R-VF prior to the third shock). To predict incessant R-VF specifically, we used a series of four 2-s ECG segments from each patient within 60s surrounding the first shock. Patients were randomized 65%/35% for training/test. A support vector machine classifier was trained to predict subsequent incessant R-VF using ECG scalograms. Algorithm performance was assessed by area under the receiver operating characteristic curve (AUC) and by sensitivity at >75% specificity. Results: Of 1111 included VF patients, median age was 62, 241 (22%) were female, 658 (59%) were refractory (≥ 3 shocks), 800 (72%) achieved ROSC, and 520 (47%) survived. The incessant R-VF phenotype accounted for 10% (N=116) and had worse ROSC and survival compared to recurrent R-VF and non-refractory patients (Table). Training and test AUCs to predict incessant R-VF were 0.77 (95% CI: 0.72–0.82, N=723) and 0.76 (95% CI: 0.66–0.82, N=388) respectively. Test sensitivity and specificity were 64% and 76%. Conclusion: Refractory VF comprises distinct phenotypes with disparate outcomes. Incessant R-VF has notably poor prognosis. Machine learning may be able to predict incessant R-VF, potentially guiding preemptive, patient-specific treatments to improve outcome.

Measuring Outcomes Relevant to the Decolletage from the Patient Perspective: Development and Validation of the BODY-Q Decolletage Scale

Abstract Background A range of cosmetic treatments to improve skin quality of the decolletage are available. To measure outcomes from the patient perspective, a rigorously developed patient-reported outcome measure is needed. Objectives To develop and validate the BODY-Q Decolletage scale. Methods Appearance-related codes from BODY-Q concept elicitation interviews were reexamined and 13 items drafted and refined through patients and clinician debriefing interviews. The scale was tested in an online international sample of women >25 years who had previously received a treatment for the decolletage, or in the past 12 months had received a cosmetic treatment at a plastic surgery or dermatology clinic. Data were analysed with both Rasch measurement theory and classical test theory. Results Interviews conducted with 15 patients and 5 clinicians led to a 16-item scale with items that covered scenarios (mirror, photos, low neckline, lay on side, breasts together, arms crossed, get up, up close), compared (other people), age (youthful, age), qualitative (attractive, healthy), color (even-colored) and texture (smooth, texture). The field-test included 334 participants. An item with poor fit to the Rasch model was dropped. Data for the remaining 15 items fit the Rasch model (Chi-square=76.72, df=60, p=0.07). All items had ordered thresholds and good item fit. All reliability statistics were >0.93. A total of 19 of 20 pre-defined hypotheses (95%) were met providing evidence of construct validity. Conclusions The Decolletage scale is available to incorporate the perspective of patients into clinical care and clinical trials of minimally invasive treatments to improve skin quality.

Abstract 4143258: Sex Differences in Health Status Outcomes: Analysis of the ISCHEMIA Randomized Clinical Trial

Background: Despite a lesser extent and severity of coronary artery disease (CAD), women had a higher burden of angina than men in the ISCHEMIA trial, suggesting that other factors may explain symptom severity in women. We aim to describe demographic and clinical characteristics, as well as differences in care patterns, associated with health status differences in women, as compared with men, in the conservative and invasive treatment groups of the ISCHEMIA trial. Methods: The ISCHEMIA trial randomized participants with moderate or severe ischemia to a routine invasive strategy of cardiac catheterization with complete revascularization plus guideline-directed medical therapy (GDMT), or an initial conservative strategy of GDMT alone with catheterization reserved for GDMT failure. Health status was a key secondary outcome. Using linear regression models we compared raw and adjusted Seattle Angina Questionnaire (SAQ) scores in women and men at baseline and at 1 year, stratified by randomized treatment strategy. Within the invasive strategy, sex differences were adjusted for completeness of revascularization among those with ≥1 coronary stenosis ≥70%. Results: Of 4,617 ISCHEMIA participants with valid SAQ data, women had lower (worse) baseline SAQ summary scores (SS) throughout follow up (Figure) after adjustment for demographics and clinical characteristics, including severity of CAD (difference 5.4 points, 95% CI 4.0-6.7). Women had lower SAQ SS after adjustment for post-randomization treatment (i.e., medical therapy, achievement of risk factor goals and, in the invasive strategy, complete revascularization), 2.4 points lower (95% CI 0.7-4.1) in the conservative group (Figure), and 1.9 points lower than in men (95% CI 0.1-3.7) in the invasive group. Findings were similar for all SAQ subscales. Conclusions: Women with chronic coronary disease in ISCHEMIA had worse health status than men at baseline and 1 year later, which was not explained by demographic or clinical characteristics, intensity of medical therapy, or completeness of revascularization.

The Diagnosis and Management of Infraoccluded Deciduous Molars: A Systematic Review

The infraocclusion (IO) of primary molars, often seen in retained deciduous teeth, is a common condition that presents significant challenges for pediatric oral health. It occurs when primary molars are positioned below the occlusal plane due to the absence of permanent successors, leading to complications such as misaligned teeth, impaired chewing, and long-term dental health issues. Objectives: This study examines IO prevalence, diagnosis, and treatment approaches. Methods: A systematic review following PRISMA guidelines was conducted, searching PubMed, Web of Science, and Scopus for articles from the last 15 years. Nine articles were included for qualitative analysis. Results: IO was associated with several complications, including root resorption, altered eruption of adjacent teeth, and space loss within the dental arch. Clinical and radiographic evaluations are key to early detection. Severe cases often require invasive treatments, such as tooth extraction and space maintenance, while mild cases could be monitored. Conclusions: IO is prevalent in pediatric dentistry and can lead to significant dental issues if untreated. Early detection and intervention are crucial for preventing complications like tooth misalignment and impacted premolars. Tailored treatment strategies based on severity, along with increased awareness among dental practitioners, are essential to improve long-term outcomes for affected children.

Ultrasound-guided percutaneous microwave ablation of primary hyperthyroidism: security and efficacy analysis

Objectives This study aimed to analyze the safety, efficacy, and application prospects of ultrasound-guided microwave ablation (MWA) in the treatment of primary hyperthyroidism. Methods Eight patients with primary hyperthyroidism who underwent ultrasound-guided glandular volume reduction between January 2021 and December 2022 were included in this study. Pre- and postablative examinations, including grayscale ultrasound, contrast-enhanced ultrasound (CEUS), laboratory examination, antithyroid drug (ATD) dosage, and quality of life (QoL) assessment via Thyroid-Specific Patient-Reported Outcome Short-Form (ThyPRO-39), were analyzed retrospectively. The main ultrasound follow-up times were 1, 3, 6, and 12 months after ablation. Thyroid function was reviewed 1 week after ablation, and the subsequent reexamination time was determined according to the patient’s specific test results and ATD adjustment. The final efficacy was comprehensively analyzed according to the patient’s medication status, thyroid function, thyroid volume, and QoL score. Results All 8 patients successfully received MWA for primary hyperthyroidism, and none of them experienced serious complications. By the end of the follow-up, 5 of the 8 patients had stopped taking ATDs, 3 of the 8 patients had reduced ATD dosages, and all of them maintained stable thyroid function. Although descriptive analysis was performed because of the small sample size, patients’ thyroid volume reduction, and obvious improvements in goiter symptoms, hyperthyroid symptoms, anxiety, etc., were observed during our follow-up. Conclusion Ultrasound-guided MWA for reducing thyroid gland volume in primary hyperthyroidism patients is a new, safe, and effective minimally invasive treatment method that is a good choice for patients who cannot or refuse traditional treatment methods.

An overview of treatment strategies for class II and class III malocclusions

Class II and class III malocclusions represent common yet complex dental conditions that affect both aesthetics and function. Managing these malocclusions requires an approach tailored to the patient's growth stage, with early interventions focusing on growth modification and adult cases often necessitating surgical solutions. In class II malocclusions, growth modification with functional appliances such as the Twin Block and Herbst appliance promotes mandibular advancement and improves facial harmony in younger patients. For older individuals or those with more severe malocclusions, orthodontic camouflage or mandibular advancement surgery, including bilateral sagittal split osteotomy, is recommended to achieve a balanced occlusal relationship and improve facial proportions. Class III malocclusions, often involving a prognathic mandible or maxillary deficiency, are particularly challenging. For young patients, facemask therapy and rapid maxillary expansion can encourage maxillary growth, while chin cup therapy can control mandibular projection, aiming to improve skeletal balance. In severe adult cases, combined orthodontic-surgical treatments, such as maxillary advancement through Le Fort I osteotomy or mandibular setback procedures, provide durable, functionally stable outcomes. Surgical-orthodontic approaches, including bimaxillary surgery, are particularly advantageous for severe class III cases by effectively addressing the underlying skeletal imbalances and enhancing facial aesthetics. Growth modification techniques emphasize the importance of early diagnosis and intervention, aiming to harness natural growth potential and reduce the need for more invasive treatments later in life. For adult patients, surgical interventions present a definitive solution, delivering substantial improvements in function and appearance. Ongoing advances in both orthodontic and surgical techniques are refining the precision and stability of treatment outcomes, underscoring the need for individualized, age-appropriate strategies in managing class II and class III malocclusions.

Endoscopic resection of a juvenile jejunum polyp which caused recurrent intestinal bleeding in a 12-month-old child: clinical observation

BACKGROUND: To verify a source of obscure gastrointestinal bleeding leading to iron deficiency anemia is a challenging diagnostic problem. Intestinal polyps can be one of such sources. Sporadic juvenile intestinal polyps are extremely rare at the first year of life. The authors present a clinical case which demonstrates endoscopic diagnostics and resection of a jejunum polyp in a 12-month-old child weighing 6.3 kg. We did not find similar publications in literature. CLINICAL CASE DESCRIPTION: A 12-month-old boy was admitted to our clinic with long-lasting complaints of dark stool and iron deficiency anemia. For the first time, gastrointestinal bleeding symptoms appeared at the age of one month. The child was repeatedly examined, but gastrointestinal bleeding source was not found. The child was prescribed symptomatic therapy for iron deficiency anemia including red blood cell transfusion. At current hospitalization in our clinic an intestinal polyp and transient small intestinal intussusception were suspected at ultrasound examination. The child underwent esophagogastroduodenoscopy, video capsule endoscopy, colonoscopy, laparoscopy. But the source of the bleeding was not found. During the repeated enteroscopy at 40 cm distally to the pylorus a sporadic juvenile jejunum polyp 17×15 mm was found and resected. The postoperative period was uneventful. In 1 month, there were no complaints as for the catamnesis, the child's stool had the usual characteristics, the indicators of "red blood" corresponded to the age norm. CONCLUSION: A sporadic juvenile jejunal polyp may be a cause of obscure recurrent intestinal bleeding in children. Modern intraluminal endoscopy allows not only to put diagnosis, but also to perform a minimally invasive surgical intervention.

NIMG-02. DEVELOPING A RADIOMIC HIERARCHICAL GAUSSIAN PROCESS BOOSTING MODEL TO PREDICT PRIMARY TUMOR ORIGIN FROM MULTICENTRIC LONGITUDINAL MRI DATA OF BRAIN METASTASES

Abstract Focal neurologic deficits due to brain metastases might be the initial presentation in patients with cancer. Common approaches to investigate the occult primary malignancy include a whole-body PET-CT, whole-body MRI, studying tumor markers, or histopathological examination. Most of these modalities are expensive, time-consuming, invasive, and delay treatment. The field of radiomics leverages quantitative features extracted from images to improve the decision-making process in clinical practices. Although not easily understandable, these features are proxies for the tumor’s shape, contour, texture, and intensity patterns. They can help understand tumor heterogeneity, predict tumor behavior, and assess treatment response. We propose a robust radiomic workflow using longitudinal MRI data from 914 high-resolution imaging studies from 12 different centers (Ocaña-Tienda et al. (2023), Ramakrishnan et al. (2023), Wang et al. (2023)) to predict the origin of brain metastases from brain MRI scans. After using ensemble feature selection methods, we trained three fixed-effects and one mixed-effects multiclass classification model to account for longitudinal data. Fixed-effects logistic regression and support vector kernel models performed the worst (AUC 0.74 and 0.75, respectively), while the random forest performed better (AUC 0.97). The mixed-effects hierarchical Gaussian process boosting (GPBoost) model performed the best with an accuracy of 85.8%, precision of 85.4%, sensitivity of 85.8%, specificity of 95.7%, and an AUC of 0.98. In one-versus-rest classification, the GPBoost model identified the primary tumor as melanoma with the highest accuracy (96.1%) and non-small cell lung cancer with the lowest accuracy (89.0%). Developing such models holds great promise in reducing patient and institutional costs, improving time to effective treatment, and enhancing overall survival rates through personalized therapy approaches. In the future, we hope that incorporating newer patient data and refining the model to improve external validity would enable more accurate and generalizable predictions, leading to better clinical outcomes across diverse populations.

TMOD-27. RECURRENT GLIOBLASTOMA AFTER LASER ABLATION OF THE PRIMARY TUMOR IN A PRECLINICAL ORTHOTOPIC MODEL EXHIBIT INCREASED GENETIC SIGNATURES OF CELL CYCLE AND CELL MOTILITY

Abstract Image-guided laser interstitial thermal therapy (LITT) is a minimally invasive tumor cytoreductive treatment for recurrent gliomas and tumors in eloquent loci. We have adapted this technique to develop an image-guided glioblastoma (GBM) ablation model, its recurrence and have tested the efficacy of imaging biomarkers in evaluating tumor ablation and recurrence. The cytopathology and molecular signatures of the primary and recurrent tumors were compared. Immune-compromised female rats were implanted with U251N tumor cells in one brain hemisphere (n=20). Tumor growth was monitored using magnetic resonance imaging (MRI). When tumors reached about 4 mm in diameter, they were ablated using a clinical LITT system (Visualase®), under MRI guidance. Five other rats implanted with U251N tumors were used as unablated controls. MRI data were acquired at 24 h post-LITT, and at 2 and 4 weeks. Rats were sacrificed for histopathology at 2 and 4 weeks, and brain sections stained for hematoxylin and eosin, human major histocompatibility complex, Ki67, a cell proliferation marker and sex determining region Y)-box 2 (SOX2), a stem cell transcription factor. An additional cohort of rats with primary (n=4) and post-LITT recurrent (n=4) U251N tumors were used for analysis of their molecular composition using RNA-Seq approach. In the treated groups, MRI showed little tumor tissue at 24 h, evidence of recurrence at 2 weeks and significant tumor tissue at 4 weeks. Tumor DCE-MRI parameters showed elevated intra-tumoral vascular permeability (i.e., Ktrans) values at pre-LITT imaging, that shifted to peri-ablation periphery at 24 h. A trend of progressive decrease in Ktrans was seen until 1-week post-ablation. Increasing Ktrans values at 2 weeks and after 4 weeks coincided with tumor recurrence. RNA-Seq data showed that cell cycle, cellular movement and inflammatory disease genes were the most differentially expressed genes in the recurrent tumors suggesting increased infiltration may primarily underlie treatment resistance.

INNV-17. SAME-DAY DISCHARGE AFTER LASER INTERSTITIAL THERMAL THERAPY: A PROSPECTIVE COHORT PILOT STUDY WITH A MATCHED CONTROL GROUP

Abstract BACKGROUND Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for intracranial pathologies, offering precision and control over tissue damage. With implementation of enhanced recovery after surgery (ERAS) protocols within neurosurgery, identifying patients amenable for same-day discharge (SDD) is an important step towards streamlining perioperative care following LITT, and correspondingly, we aim to summarize our initial experience. METHODS We conducted a prospective study at the University of Miami Hospital of 7 patients who underwent LITT for intracranial pathologies and were discharged on the same day of ablation (post-ablation day 0, PAD0). We then performed a retrospective case-control study against a historic matched PAD1 cohort comparing categorical and continuous variables for statistical significance. RESULTS The mean age of the PAD0 cohort was 55 years with 71% males. Preoperative neurological status and comorbidities did not differ significantly between the PAD0 and PAD1 cohorts for KPS (median [IQR]: 80 [80-90] vs. 90 [80-90], p=0.40), mFI-5 (median [IQR]: 1 [1.5] vs. 0 [1], p=0.54), and mFI-11 (median [IQR]: 1 [1.5] vs. 1 [1], p=0.52). PAD0 outcomes demonstrated no immediate complications, neurosurgical readmissions, or significant neurological deficits within 6 months post-procedure and were non-significantly different than PAD1 patients. No PAD0 patient experienced intracranial hemorrhage or vasogenic edema following LITT that necessitated further intervention. CONCLUSIONS Our study demonstrates the safety and feasibility of same-day discharge following LITT for intracranial pathologies in the appropriately selected patient. Through meticulous patient selection and optimized perioperative protocols, expedited recovery without compromising patient outcomes was achieved. This approach holds potential for substantial cost savings and resource optimization within healthcare systems. Further research and quality improvement initiatives are warranted to refine patient selection criteria and maximize the benefits of same-day discharge in LITT practice.

SURG-36. ACCURACY OF THE ROSA ONE BRAIN ROBOTIC PLATFORM FOR THE PLACEMENT OF NEUROBLATE AND VISUALASE LASER INTERSTITIAL THERMAL THERAPY PROBES

Abstract Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for patients with intracranial lesions. The success of LITT is dependent on accurate placement of the laser probe in target tissue. Placement can be facilitated by various stereotactic methods, including the Robotic Surgical Assistant (ROSA) ONE Brain robotic platform. The aim of this study is to examine the accuracy of stereotactic probe placement utilizing the ROSA robot. Primary outcomes were entry distance, target distance, and entry angle error. Accuracy differences between two major LITT platforms, the Neuroblate (Monteris Medical) and Visualase Systems, were compared. A prospective institutional database was used to identify all patients who underwent LITT for intracranial tumors utilizing the ROSA robot between 2013-2023. The sign test was used to compare error values to test their difference from a null value of 0. Spearman correlation was used to assess the relationship between angle of error and trajectory length. Kuskal-Wallis test was used to compare errors and trajectory length between the two companies. Of the 105 patients who underwent LITT during the study period, 337 probes were placed. For Visualase probes, median entry distance (1.1mm, IQR=0.4-2.0), target distance (1.6mm, IQR =0.9-2.4), and entry angle error (1.5°, IQR=0.9-2.5), were significantly different than zero (p=<.0001). For Neuroblate probes, median entry distance (1.5mm, IQR=1.0-2.1), target distance (1.8mm, IQR=1.1-2.4), and entry angle error (1.8°, IQR=1.1-2.5) were significantly different than zero (p=<.0001). When comparing laser systems, there was a significant difference in median entry distance error with Neuroblate having a higher error (1.5mm, IQR=1.0-2.1) than Visualase (1.1mm IQR=0.4-2.0, p=0.0041). Stereotactic placement of LITT probes utilizing the ROSA robotic system was not able to achieve perfect alignment with the planned trajectory. When comparing the systems, Visualase probes were placed more accurately at the entry point than Neuroblate probes.

SURG-28. THE IMPACT OF PERILESIONAL HEATSINK STRUCTURES ON ABLATION VOLUMES AND SYMMETRY IN LASER INTERSTITIAL THERMAL THERAPY FOR THE TREATMENT OF PRIMARY CENTRAL NERVOUS SYSTEM TUMORS

Abstract BACKGROUND Laser Interstitial Thermal Therapy (LITT) has emerged as a minimally invasive treatment for primary CNS tumors. While LITT offers advantages over traditional approaches, perilesional intracranial heatsinks can lead to asymmetric ablation, impacting patient outcomes. Understanding heatsink effects is crucial for optimizing LITT efficacy. METHODS We retrospectively analyzed primary CNS tumors treated with LITT at a single tertiary care center. Ablation outcomes were quantified using the Heatsink Effect Index (HEI) measured on a scale of 0-1 (0=total symmetry; 1=complete asymmetry), and extent of ablation (EOA). Heatsink types evaluated were sulci, meninges, vasculature, and cerebrospinal fluid (CSF) spaces, inclusive of ventricles, surgical resection cavities, and CSF cisterns. Statistical analyses assessed the relationship between heatsink proximity and ablation outcomes. RESULTS A total of 99 patients satisfied all selection criteria. The cohort was 53% female, with a mean age of 61 years. Glioblastoma was the most predominant tumor type (78%), followed by low grade gliomas (15%), and meningiomas (4%). Heatsink proximity significantly correlated with ablation asymmetry (HEI) (p < 0.001), particularly at the midpoint of the catheter trajectory. The correlation between closest heatsink distance and HEI varied across the different heatsink types, with distance to vasculature and CSF spaces correlating the strongest with ablation asymmetry. When assessing the relationship between EOA and medial HEI during suboptimal ablations (EOA < 100%), we demonstrated a negative correlation showing improved EOA as HEI was reduced. Optimal cutoff catheter-heatsink distances for predicting ablation asymmetry ranged from 6.6-13.0 mm, emphasizing the impact of heatsink proximity on LITT efficacy. CONCLUSION We show that proximity to heatsinks, especially within a threshold distance of 13.0mm from the laser catheter, significantly predicts ablation asymmetry and volume in the setting of primary CNS tumors. Neurosurgeons should consider heatsink effects in pre- and intraoperative planning to optimize LITT outcomes and preserve normal brain tissue.