Clinical validation of 3D virtual modelling for laparoscopic complete mesocolic excision with central vascular ligation for proximal colon cancer.

INTRODUCTION: Laparoscopic Complete Mesocolic Excision (CME) with Central Vascular Ligation (CVL) in colon cancer surgery has not been broadly adopted in part because of safety concerns. Pre-operative 3-D virtual modelling (3DVM) may help but needs validation. METHODS: 3DVM were routinely constructed from CT mesenteric angiograms (CTMA) using a commercial service (Visible Patient, Strasbourg, France) for consecutive patients during our CMECVL learning curve over three years. 3DVMs were independently checked versus CTMA and operative findings. CMECVL outcomes were compared versus other patients undergoing standard mesocolic excision (SME) surgery laparoscopically in the same hospital as control. Stakeholders were studied regarding 3DVM use and usefulness (including detail retention) versus CTMA and a physical 3D-printed model. RESULTS: 26 patients underwent 3DVM with intraoperative display during laparoscopic CMECVL within existing workflows. 3DVM accuracy was 96 % re arteriovenous variations at patient level versus CTMA/intraoperative findings including accessory middle colic artery identification in three patients. Twenty-two laparoscopic CMECVL with 3DVM cases were compared with 49 SME controls (age 69 ± 10 vs 70.9 ± 11 years, 55 % vs 53 % males). There were no intraoperative complications with CMECVL and similar 30-day postoperative morbidity (30 % vs 29 %), hospital stay (9 ± 3 vs 12 ± 13 days), 30-day readmission (6 % vs 4 %) and reoperation (0 % vs 4 %) rates. Intraoperative times were longer (215.7 ± 43.9 vs 156.9 ± 52.9 min, p=<0.01) but decreased significantly over time. 3DVM surveys (n = 98, 20 surgeons, 48 medical students, 30 patients/patient relatives) and comparative study revealed majority endorsement (90 %) and favour (87 %). CONCLUSION: 3DVM use was positively validated for laparoscopic CMECVL and valued by clinicians, students, and patients alike.

Impact of Simulation Training on Core Skill Competency of Undergraduate Medical Students.

INTRODUCTION: Simulation based medical training (SBMT) is gaining traction for undergraduate learning and development. We designed, implemented, and independently assessed the impact of an SBMT programme on competency in surgical history taking and clinical examination for senior clinical students. METHODS: With institutional ethical approval and initial pilot study of student volunteers that ensured format appropriateness, we implemented an SBMT programme weekly for ten weeks during the core surgery module of our Medicine degree programme. Groups of 5 students collaboratively undertook an observed focused history and physical examination while simultaneously directing care on a simulated surgical patient (actor) with acute abdominal pain. This was conducted in a nonclinical, standardised, tutor-supervised environment and followed by a group debriefing led by both the simulated patient and tutor discussing student interaction and competency. All students undertook Southampton Medical Assessment Tool (SMAT) on a surgical inpatient prior to (baseline) and within 2 weeks after SBMT. Students without simulation training functioned as a control group and randomized cluster sampling was utilised for group selection. Second assessments were by independent surgical academics blinded to student group. Feedback was collected via anonymous questionnaire from those who undertook SBMT. RESULTS: One hundred students took part, fifty of whom undertook SBMT. Global mean SMAT scores were similar between the control and intervention group at baseline (p > 0.05). Scores on the second assessment were significantly higher (p = 0.0006) for those who had undertaken SBMT vs. controls; 94% of students taking SBMT reported benefit via questionnaire with 85% stating increased confidence in history-taking and 78% reporting improved abdominal examination. CONCLUSIONS: Undergraduate simulation training at scale is feasible and positively impacts undergraduate student core task competency.

Clinical and computational development of a patient-calibrated ICGFA bowel transection recommender.

INTRODUCTION: Intraoperative indocyanine green fluorescence angiography (ICGFA) aims to reduce colorectal anastomotic complications. However, signal interpretation is inconsistent and confounded by patient physiology and system behaviours. Here, we demonstrate a proof of concept of a novel clinical and computational method for patient calibrated quantitative ICGFA (QICGFA) bowel transection recommendation. METHODS: Patients undergoing elective colorectal resection had colonic ICGFA both immediately after operative commencement prior to any dissection and again, as usual, just before anastomotic construction. Video recordings of both ICGFA acquisitions were blindly quantified post hoc across selected colonic regions of interest (ROIs) using tracking-quantification software and computationally compared with satisfactory perfusion assumed in second time-point ROIs, demonstrating 85% agreement with baseline ICGFA. ROI quantification outputs detailing projected perfusion sufficiency-insufficiency zones were compared to the actual surgeon-selected transection/anastomotic construction site for left/right-sided resections, respectively. Anastomotic outcomes were recorded, and tissue lactate was also measured in the devascularised colonic segment in a subgroup of patients. The novel perfusion zone projections were developed as full-screen recommendations via overlay heatmaps. RESULTS: No patient suffered intra- or early postoperative anastomotic complications. Following computational development (n = 14) the software recommended zone (ROI) contained the expert surgical site of transection in almost all cases (Jaccard similarity index 0.91) of the nine patient validation series. Previously published ICGFA time-series milestone descriptors correlated moderately well, but lactate measurements did not. High resolution augmented reality heatmaps presenting recommendations from all pixels of the bowel ICGFA were generated for all cases. CONCLUSIONS: By benchmarking to the patient's own baseline perfusion, this novel QICGFA method could allow the deployment of algorithmic personalised NIR bowel transection point recommendation in a way fitting existing clinical workflow.

Multidisciplinary Surgical Approach to Increase Survival for Advanced Ovarian Cancer in a Tertiary Gynaecological Oncology Centre.

PURPOSE: The purpose of this paper is to report on changes in overall survival, progression-free survival, and complete cytoreduction rates in the 5-year period after the implementation of a multidisciplinary surgical team (MDT). METHODS: Two cohorts were used. Cohort A was a retrospectively collated cohort from 2006 to 2015. Cohort B was a prospectively collated cohort of patients from January 2017 to September 2021. RESULTS: This study included 146 patients in cohort A (2006-2015) and 174 patients in cohort B (2017-2021) with FIGO stage III/IV ovarian cancer. Median follow-up in cohort A was 60 months and 48 months in cohort B. The rate of primary cytoreductive surgery increased from 38% (55/146) in cohort A to 46.5% (81/174) in cohort B. Complete macroscopic resection increased from 58.9% (86/146) in cohort A to 78.7% (137/174) in cohort B (p < 0.001). At 3 years, 75% (109/144) patients had disease progression in cohort A compared with 48.8% (85/174) in cohort B (log-rank, p < 0.001). Also at 3 years, 64.5% (93/144) of patients had died in cohort A compared with 24% (42/174) of cohort B (log-rank, p < 0.001). Cox multivariate analysis demonstrated that MDT input, residual disease, and age were independent predictors of overall (hazard ratio [HR] 0.29, 95% confidence interval [CI] 0.203-0.437, p < 0.001) and progression-free survival (HR 0.31, 95% CI 0.21-0.43, p < 0.001). Major morbidity remained stable throughout both study periods (2006-2021). CONCLUSIONS: Our data demonstrate that the implementation of multidisciplinary-team, intraoperative approach allowed for a change in surgical philosophy and has resulted in a significant improvement in overall survival, progression-free survival, and complete resection rates.

Understanding surgical smoke in laparoscopy through Lagrangian Coherent Structures.

In laparoscopic surgery, one of the main byproducts is the gaseous particles, called surgical smoke, which is found hazardous for both the patient and the operating room staff due to their chemical composition, and this implies a need for its effective elimination. The dynamics of surgical smoke are monitored by the underlying flow inside the abdomen and the hidden Lagrangian Coherent Structures (LCSs) present therein. In this article, for an insufflated abdomen domain, we analyse the velocity field, obtained from a computational fluid dynamics model, first, by calculating the flow rates for the outlets and then by identifying the patterns which are responsible for the transportation, mixing and accumulation of the material particles in the flow. From the finite time Lyapunov exponent (FTLE) field calculated for different cross-sections of the domain, we show that these material curves are dependent on the angle, positions and number of the outlets, and the inlet. The ridges of the backward FTLE field reveal the regions of vortex formation, and the maximum accumulation, details which can inform the effective placement of the instruments for efficient removal of the surgical smoke.

Clinical Experience of a Smart Articulating Digital Device for Transanal Minimally Invasive Surgery.

BACKGROUND: The constrained access associated with transanal minimally invasive surgery has led surgeons to deploy robotic-assisted platforms to offset inherent maneuverability limitations and, perhaps, skills deficits. IMPACT OF INNOVATION: A handheld, powered 5-mm lightweighted laparoendoscopic electromechanical digital device (HandX, HumanXtensions, Israel) with hardware and software components that convert surgical hand movements precisely to the instrument's articulating tip and enable robotic transanal minimally invasive surgery with full tip roticulation for hook diathermy and suturing. TECHNOLOGY, MATERIALS, AND METHODS: After bench and biomedical model training, HandX was used in 3 transanal minimally invasive surgery procedures (2 male patients and 1 female patient, mean age 66.3 years). The rectal lesions averaged 30 mm in maximum dimension and were located posteriorly (n = 2) and laterally (n = 1) a mean of 3 cm from the anal verge. Standard transanal minimally invasive surgery setup and instrumentation (Gelport Path, Applied Medical with Airseal, and Conmed) were used, adding the HandX device for circumferential lesion marking and hemostatic full-thickness excision as well as defect suturing where appropriate. PRELIMINARY RESULTS: All procedures were completed without undue prolongation (operating times <1 hour) despite nuisance hemorrhoidal bleeding in 1 patient. All lesions were fully excised, with 2 being T1 cancers and 1 tubulovillous adenoma with high-grade dysplasia. All patients were discharged within 48 hours postoperatively (1 experienced secondary hemorrhage on postoperative day 5). CONCLUSIONS AND FUTURE DIRECTIONS: HandX capably facilitated endoscopic robot-like instrument movement for transanal minimally invasive surgery without disrupting workflows. With time dedicated to instrument understanding and training, HandX increased dexterity with a small operating room footprint and may offer greater cost-effectiveness than other platforms.

Implementation of an on-site simulation programme during COVID-19 and the assessment of its impact on medical students' competence.

BACKGROUND: COVID-19 has greatly impacted medical students' clinical education. This study evaluates the usefulness of a rapidly implemented on-site simulation programme deployed to supplement our disrupted curriculum. METHODS: Students on surgical rotations received 4-hour tutor-led simulated patient sessions (involving mannikins with remote audio-visual observation) respecting hospital and public health protocols. Attitudes were questionnaire-assessed before and after. Independent, blinded, nonacademic clinicians scored students' clinical competencies by observing real patient interactions using the surgical ward assessment tool in a representative sample versus those completing same duration medicine clinical rotations without simulation (Mann-Whitney U testing, p < 0.05 denoting significance) with all students receiving the same surgical e-learning resources and didactic teaching. RESULTS: A total of 220 students underwent simulation training, comprising 96 hours of scheduled direct teaching. Prior to commencement, 15 students (7% of 191 completing the survey) admitted anxiety, mainly due to clinical inexperience, with only two (1%) anxious re on-site spreading/contracting of COVID-19. A total of 66 students (30%, 38 females and 29 graduate entrants) underwent formal competency assessment by clinicians from ten specialties at two clinical sites. Those who received simulation training (n = 35) were judged significantly better at history taking (p = 0.004) and test ordering (p = 0.01) but not clinical examination, patient drug chart assessment, or differential diagnosis formulation. Of 75 students providing subsequent feedback, 88% stated simulation beneficial (notably for history taking and physical examination skills in 63%) with 83% advocating for more. CONCLUSION: Our rapidly implemented simulation programme for undergraduate medical students helped mitigate pandemic restrictions, enabling improved competence despite necessarily reduced clinical activity encouraging further development.

Impact of intra-abdominal insufflation pressure on gas leakage occurring during laparoscopy.

INTRODUCTION: The advent of the COVID-19 pandemic led to recommendations aimed at minimizing the risk of gas leaks at laparoscopy. As this has continuing relevance including regarding operating room pollution, we empirically quantified carbon dioxide (CO2) leak jet velocity (important for particle propulsion) occurring with different instruments inserted into differing trocars repeated across a range of intra-abdominal pressures (IAPs) and modern insufflators in an experimental model. METHOD: Laparoscopic gas plume leak velocity (metres/second) was computationally enumerated from schlieren optical flow videography on a porcine cadaveric laparoscopic model with IAPs of 4-5, 7-8, 12-15 and 24-25 mmHg (repeated with 5 different insufflators) during simulated operative use of laparoscopic clip appliers, scissors, energy device, camera and staplers as well as Veres needle (positive control) and trocar obturator (negative control) in fresh 5 mm and 12 mm ports. RESULTS: Close-fitting solid instruments (i.e. cameras and obturators) demonstrated slower gas leak velocities in both the 5 mm and 12 mm ports (p = 0.02 and less than 0.001) when compared to slimmer instruments, however, hollow instrument designs were seen to defy this pattern with the endoscopic linear stapler visibly inducing multiple rapid jests even when compared to similarly sized clip appliers (p = 0.03). However, on a per device basis the operating instrumentation displayed plume speeds which did not vary significantly when challenged with varying post size, IAP and a range of insufflators. CONCLUSION: In general, surgeon's selection of instrument, port or pressure does not usefully mitigate trocar CO2 leak velocity. Instead better trocar design is needed, helped by a fuller understanding of trocar valve mechanics via computational fluid dynamics informed by relevant surgical modelling.

User Evaluation of a Novel Smart Insufflator for Laparoscopic Surgery-The EVA-15.

INTRODUCTION: There is resurging interest in the importance of effective, nuanced insufflation and personalised pneumoperitoneal pressure-management during laparoscopy. Here, we present user-evaluation data from a regulated, prospective, multispecialty study of a new insufflator (EVA-15, Palliare, Galway, Ireland) which provides high-frequency pressure-sensing, built-in smoke evacuation with pedal activation and highly responsive, high-flow gas provision. METHODS: With institutional ethics and regulatory body approval, a non-randomised, prospective clinical investigation was performed on 30 subjects undergoing laparoscopic surgery using an EVA-15 device. Cases were selected from a variety of specialties on a near-consecutive basis without specific exclusion criteria. Users (both surgeons and operating room nurses) completed a survey at case completion to capture ordinal categorical data on a 5-point Likert agreement scale (1 - Strongly disagree to 5 - Strongly agree) concerning (i) Settings and Setup Evaluations, (ii) Alarms and Displays Evaluations, (iii) Short Instruction Guide, and (iv) Insufflator Performance along with any additional feedback. RESULTS: Operations on 30 patients (mean age 54 y, 15 males) were studied with a questionnaire completed by operating room teams after individual consent. The procedures included general (n=13), upper (n=3) and lower (n=6) gastrointestinal surgery, bariatric (n=3), hepatobiliary (n=2) urology (n=2, both robotic prostatectomy) and gynaecology (n=1) operations. In all cases, the laparoscopic component was completed capably with the use of the EVA-15 device. The insufflator evaluation score across all categories was a median of 4, demonstrating satisfactory use and performance in all regards. CONCLUSION: The EVA-15 is a smart insufflator system that is capable of satisfactory performance across a spectrum of cases among different specialties.

Digital dynamic discrimination of primary colorectal cancer using systemic indocyanine green with near-infrared endoscopy.

As indocyanine green (ICG) with near-infrared (NIR) endoscopy enhances real-time intraoperative tissue microperfusion appreciation, it may also dynamically reveal neoplasia distinctively from normal tissue especially with video software fluorescence analysis. Colorectal tumours of patients were imaged mucosally following ICG administration (0.25 mg/kg i.v.) using an endo-laparoscopic NIR system (PINPOINT Endoscopic Fluorescence System, Stryker) including immediate, continuous in situ visualization of rectal lesions transanally for up to 20 min. Spot and dynamic temporal fluorescence intensities (FI) were quantified using ImageJ (including videos at one frame/second, fps) and by a bespoke MATLAB® application that provided digitalized video tracking and signal logging at 30fps (Fluorescence Tracker App downloadable via MATLAB® file exchange). Statistical analysis of FI-time plots compared tumours (benign and malignant) against control during FI curve rise, peak and decline from apex. Early kinetic FI signal measurement delineated discriminative temporal signatures from tumours (n = 20, 9 cancers) offering rich data for analysis versus delayed spot measurement (n = 10 cancers). Malignant lesion dynamic curves peaked significantly later with a shallower gradient than normal tissue while benign lesions showed significantly greater and faster intensity drop from apex versus cancer. Automated tracker quantification efficiently expanded manual results and provided algorithmic KNN clustering. Photobleaching appeared clinically irrelevant. Analysis of a continuous stream of intraoperatively acquired early ICG fluorescence data can act as an in situ tumour-identifier with greater detail than later snapshot observation alone. Software quantification of such kinetic signatures may distinguish invasive from non-invasive neoplasia with potential for real-time in silico diagnosis.

Short-term outcomes in older patients with peritoneal malignancy treated with cytoreductive surgery and HIPEC: Experience with 245 patients from a national centre.

BACKGROUND: Cytoreductive Surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly accepted as the optimal management of selected patients with peritoneal malignancy. There is limited published evidence on outcomes in older patients treated by this complex therapeutic strategy. METHODS: A retrospective review of a prospective database of all patients who underwent CRS with HIPEC in a single institution over seven years. A comparative analysis of outcomes in patients under 65 undergoing CRS and HIPEC with patients ≥65 years was performed. The key endpoints were morbidity, mortality, reintervention rate and length of stay in the high dependency/intensive care (HDU/ICU) units. RESULTS: Overall, 245 patients underwent CRS and HIPEC during the study period, with 76/245 (31%) ≥65 years at the time of intervention. Tumour burden measured by the peritoneal carcinomatosis index (PCI) score was a median of 11 for both groups. Median length of hospital stay in the ≥65-year-old group was 14.5 days versus 13 days in the <65-year-old group (∗p = 0.01). Patients aged ≥65-years spent a median of one more day in the critical care unit ∗(p = 0.001). Significant morbidity (Clavien-Dindo ≥ Grade IIIa) was higher in the ≥65-year than the <65-year group (18.4% versus 11.2%). There were no perioperative deaths in the ≥65-year group. CONCLUSION: This study demonstrates higher perioperative major morbidity in ≥65-year group, but with low mortality in patients undergoing CRS/HIPEC for disseminated intraperitoneal malignancy. This increased morbidity does not translate into higher rates of re-interventions and highlights the importance of optimal patient selection.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: outcomes from a national centre in the current era.

BACKGROUND: Multimodal therapy incorporating cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival for selected patients with colorectal peritoneal metastases (CPMs). Many countries have centralised management of these patients, aiming to improve outcomes. There is ongoing debate on the need for and complications associated with HIPEC administration. We report indications and outcomes after CRS/HIPEC treated in a national centre in the modern era. METHODS: A retrospective review of all CPM patients who underwent CRS and HIPEC since the initiation of an Irish national program in 2013. The primary endpoint was the overall survival associated with CRS/HIPEC. RESULTS: During the study period (April 2013-June 2020), 123 patients proceeded to planned CRS/HIPEC for CPM. Median age was 58 (IQR 47-67) and 55 patients (44.7%) were male. In 65 patients (52.8%), CPM was synchronous. In 7/123 (5.8%), disease was unresectable. The median peritoneal cancer index (PCI) was 10 (IQR 5-17). Overall, 104/123 (84.5%) underwent a complete cytoreduction (CC0/CC1). Thirteen out of 123 (10.5%) patients also had a synchronous liver resection. Forty out of 123 (32.5%) patients had adverse pathological features (poorly differentiated or signet ring cells). The median survival in patients after CC0, CC1 and CC2/3 resection was 50, 18 and 11 months respectively (*p = < 0.0001, Log-rank Mantel-Cox). In total, 14/123(11.4%) had a major post-operative complication and 4/123 (3.3%) required re-operation. There was one (0.8%) post-operative death. The median length of stay was 14 days (IQR 9-19). CONCLUSION: This study reports encouraging outcomes in patients with CPM undergoing CRS and HIPEC, especially when complete cytoreduction is achieved.

Inter-user variation in the interpretation of near infrared perfusion imaging using indocyanine green in colorectal surgery.

INTRODUCTION: Despite increasing endorsement of near-infrared perfusion assessment using indocyanine green (ICG) during colorectal surgery, little work has yet been done regarding learning curve and interobserver variation most especially on surgical video reflective of real-world usage. METHODS: Surgeons with established expertise in ICG usage were invited to participate in the study along with others without such experience including trainees. All participants completed an opinion questionnaire and interpreted video presentations of fluorescence angiograms in a variety of colorectal case scenarios. An interactive video platform (Mindstamp) enabled dynamic annotation. Statistical analysis of data was performed using Kruskal-Wallis and Mann-Whitney testing as well as Intraclass Correlation Coefficients and Fleiss Multi-rater Kappa Scoring. RESULTS: Forty participants (six experts) completed questionnaire data and provided judgement of 14 videos (nine showing proximal colonic transection site perfusion, four showing completed anastomoses and one an acutely strangulated bowel). 70% felt > 10 cases were needed for competency in use with the majority of experts advocating > 50 (p < 0.05). Overall agreement among experts was "good" for videos showing colonic transection perfusion (versus "moderate" among in-experts) with experts clustering more distally. In contrast, there was no interpretation concordance among experts or in-experts when judging ICG perfusion sufficiency on a yes/no basis. CONCLUSION: Significant experience is recommended before reliance on ICG perfusion angiograms. ICG fluorescence assessment is prone to variable interpretation and influenced by experience and, perhaps, knowledge of preassessment operative steps suggesting a role for objective flow analysis with artificial intelligence methods as the next phase of this technology.