Using Systems Engineering and Implementation Science to Design an Implementation Package for Preoperative Comprehensive Geriatric Assessment Among Older Adults Having Major Abdominal Surgery: Protocol for a 3-Phase Study.

BACKGROUND: Older Americans, a growing segment of the population, have an increasing need for surgical services, and they experience a disproportionate burden of postoperative complications compared to their younger counterparts. A preoperative comprehensive geriatric assessment (pCGA) is recommended to reduce risk and improve surgical care delivery for this population, which has been identified as vulnerable. The pCGA optimizes multiple chronic conditions and factors commonly overlooked in routine preoperative planning, including physical function, polypharmacy, nutrition, cognition, mental health, and social and environmental support. The pCGA has been shown to decrease postoperative morbidity, mortality, and length of stay in a variety of surgical specialties. Although national guidelines recommend the use of the pCGA, a paucity of strategic guidance for implementation limits its uptake to a few academic medical centers. By applying implementation science and human factors engineering methods, this study will provide the necessary evidence to optimize the implementation of the pCGA in a variety of health care settings. OBJECTIVE: The purpose of this paper is to describe the study protocol to design an adaptable, user-centered pCGA implementation package for use among older adults before major abdominal surgery. METHODS: This protocol uses systems engineering methods to develop, tailor, and pilot-test a user-centered pCGA implementation package, which can be adapted to community-based hospitals in preparation for a multisite implementation trial. The protocol is based upon the National Institutes of Health Stage Model for Behavioral Intervention Development and aligns with the goal to develop behavioral interventions with an eye to real-world implementation. In phase 1, we will use observation and interviews to map the pCGA process and identify system-based barriers and facilitators to its use among older adults undergoing major abdominal surgery. In phase 2, we will apply user-centered design methods, engaging health care providers, patients, and caregivers to co-design a pCGA implementation package. This package will be applicable to a diverse population of older patients undergoing major abdominal surgery at a large academic hospital and an affiliate community site. In phase 3, we will pilot-test and refine the pCGA implementation package in preparation for a future randomized controlled implementation-effectiveness trial. We anticipate that this study will take approximately 60 months (April 2023-March 2028). RESULTS: This study protocol will generate (1) a detailed process map of the pCGA; (2) an adaptable, user-centered pCGA implementation package ready for feasibility testing in a pilot trial; and (3) preliminary pilot data on the implementation and effectiveness of the package. We anticipate that these data will serve as the basis for future multisite hybrid implementation-effectiveness clinical trials of the pCGA in older adults undergoing major abdominal surgery. CONCLUSIONS: The expected results of this study will contribute to improving perioperative care processes for older adults before major abdominal surgery. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/59428.

Clinical Efficacy of Electroacupuncture at Sacral Four Points Combined with Moxibustion at Abdominal Three Points for Treating Post-Stroke Urinary Incontinence: Observations on Urodynamics, Quality of Life, and Safety.

BACKGROUND: Urinary incontinence is a common complication following a stroke. No specific drugs are available in Western medicine, and surgical treatment is highly traumatic, limiting its clinical application. This study aimed to observe the clinical efficacy of electroacupuncture at the "Sacral Four Points" combined with moxibustion at the "Abdominal Three Points" on post-stroke urinary incontinence, exploring its impact on urodynamics and quality of life. METHODS: Patients with post-stroke urinary incontinence treated at our Hospital from January 2021 to December 2023 were recruited. The study included 117 patients: 57 in the electroacupuncture group and 60 in the combined group. Urodynamic parameters were measured, and scores from the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) and the Incontinence Quality of Life Questionnaire (I-QOL) were recorded before, and after the first and third courses of treatment. Clinical efficacy and adverse reactions were evaluated post-treatment. RESULTS: The study found no significant differences in clinical characteristics between the groups (p > 0.05), providing a baseline for comparison. Both groups showed substantial decreases in leakage volume after one course of treatment (p < 0.05), with a reduction in the ICIQ-UI SF score (p < 0.05) and an increase in the I-QOL score (p < 0.05). After three courses of treatment, the leakage volume of patients in both groups significantly decreased (p < 0.05), the ICIQ-UI SF score decreased (p < 0.05), and the I-QOL score increased (p < 0.05). The combined group showed a lower leakage volume compared to the electroacupuncture group (p < 0.05), with lower ICIQ-UI SF scores (p = 0.027) and higher I-QOL scores (p = 0.048). Importantly, the total effective rate was significantly higher in the combined group (88.33% vs 64.91%, p = 0.037), demonstrating the safety and efficacy of the treatment. CONCLUSIONS: Electroacupuncture at the "Sacral Four Points" combined with moxibustion at the "Abdominal Three Points" improves the clinical symptoms and enhances the quality of life for patients with post-stroke urinary incontinence, showing superior results compared to electroacupuncture alone.

Multiple Synchronous Thoracoabdominal Duplication Cysts With Ectopic Gastric Mucosa Detected on 99mTc-Pertechnetate Scintigraphy and SPECT/CT.

ABSTRACT: Thoracoabdominal duplication cysts are a congenital malformation of the posterior primitive foregut with synchronous thoracic and abdominal duplication cysts being found in up to 15% of cases. The presentation of duplication cysts depends on their location, size, and other factors, like the presence of ectopic functioning gastric mucosa, which is reported in 20%-30% of duplication cysts. 99mTc-pertechnetate scintigraphy along with SPECT/CT helps in the preoperative localization of ectopic functioning gastric mucosa in these duplication cysts. We report the scintigraphic and SPECT/CT findings of one such case, which helped in the final diagnosis and management of the patient.

Comparison of prewarming plus intraoperative warming with intraoperative warming alone in patients undergoing minimally invasive thoracic or abdominal surgery: A systematic review and meta-analysis.

OBJECTIVE: Prewarming has been recommended to reduce intraoperative hypothermia. However, the evidence is unclear. This review examined if prewarming can prevent intraoperative hypothermia in patients undergoing thoracoscopic and laparoscopic surgeries. METHODS: PubMed, CENTRAL, Web of Science, and Embase databases were searched for randomized controlled trials (RCTs) up to 15th January 2024. The primary outcome of interest was the difference in intraoperative core temperature. The secondary outcomes were intraoperative hypothermia (<36°) and postoperative shivering. RESULTS: Seven RCTs were eligible. Meta-analysis showed that intraoperative core temperature was significantly higher at the start or within 30mins of the start of the surgery (MD: 0.32 95% CI: 0.15, 0.50 I2 = 94% p = 0.0003), 60 mins after the start of the surgery (MD: 0.37 95% CI: 0.24, 0.50 I2 = 81% p<0.00001), 120 mins after the start of the surgery (MD: 0.34 95% CI: 0.12, 0.56 I2 = 88% p = 0.003), and at the end of the surgery (MD: 0.35 95% CI: 0.25, 0.45 I2 = 61% p<0.00001). The incidence of shivering was also significantly lower in the prewarming group (OR: 0.18 95% CI: 0.08, 0.43 I2 = 0%). Prewarming was also associated with a significant reduction in the risk of hypothermia (OR: 0.20 95% CI: 0.10, 0.41 I2 = 0% p<0.0001). The certainty of the evidence assessed by GRADE was "moderate" for intraoperative core temperatures at all time points and "low" for minimal intraoperative core temperature, shivering, and hypothermia. CONCLUSION: Moderate to low-quality evidence shows that prewarming combined with intraoperative warming, as compared to intraoperative warming alone, can improve intraoperative temperature control and reduce the risk of hypothermia and shivering in patients undergoing thoracoscopic and laparoscopic procedures.

A comparative analysis of elevated endotracheal tube cuff pressure incidence in laparoscopic abdominal surgery: saline versus air inflation.

BACKGROUND: Endotracheal intubation is a frequently performed procedure in anesthesia practice, and ensuring the correct inflation of the cuff is essential for maintaining the airway seal. Overinflation of endotracheal tube (ETT) cuffs can lead to complications, such as postoperative sore throat. This study aimed to compare the incidence of elevated ETT cuff pressure between saline and air inflation in elective laparoscopic abdominal surgery. METHODS: The study involved 60 participants ranging in age from 18 to 65, with American Society of Anesthesiologists physical status levels 1-2, who underwent laparoscopic abdominal surgery. We randomly assigned patients to two groups: Group A (air-filled ETT cuffs, N.=30) and Group S (saline-filled ETT cuffs, N.=30). Intra-cuff pressure was recorded before and after CO2 insufflation, as well as during changes in patient position. The number of interventions to restore intra-cuff pressure to 18 mmHg was documented. Peak airway pressure, plateau pressure, and positive end-expiratory pressure (PEEP) were measured at 15-minute intervals. RESULTS: The number of interventions needed to maintain intra-cuff pressure was significantly lower in the saline group compared to the air group. All patients started with initial cuff pressures above 20 mmHg. After insufflation, the first-minute cuff pressures were higher in the air group (P=0.001). Both groups experienced a significant increase in intra-cuff pressure with the Trendelenburg position, and after moving to the reverse Trendelenburg position (saline and air groups, P=0.001 and 0.012, respectively), the air group had higher intra-cuff pressure than the saline group (P=0.002). There were no significant differences between groups in peak airway pressure, plateau pressure, and PEEP. CONCLUSIONS: Inflating ETT cuffs with saline instead of air during laparoscopic abdominal surgeries led to a reduced requirement for interventions in maintaining pressure. This indicates that the use of saline inflation may significantly lower the risk of high cuff pressure and related complications.

Postoperative pulmonary complications after major abdominal surgery in elderly patients and its association with patient-controlled analgesia.

OBJECTIVES: This study aims to identify the risk factors for postoperative pulmonary complications (PPCs) in elderly patients undergoing major abdominal surgery and to investigate the relationship between patient-controlled analgesia (PCA) and PPCs. DESIGN: A retrospective study. METHOD: Clinical data and demographic information of elderly patients (aged ≥ 60 years) who underwent upper abdominal surgery at the First Affiliated Hospital of Sun Yat-sen University from 2017 to 2019 were retrospectively collected. Patients with PPCs were identified using the Melbourne Group Scale Version 2 scoring system. A directed acyclic graph was used to identify the potential confounders, and multivariable logistic regression analyses were conducted to identify independent risk factors for PPCs. Propensity score matching was utilized to compare PPC rates between patients with and without PCA, as well as between intravenous PCA (PCIA) and epidural PCA (PCEA) groups. RESULTS: A total of 1,467 patients were included, with a PPC rate of 8.7%. Multivariable analysis revealed that PCA was an independent protective factor for PPCs in elderly patients undergoing major abdominal surgery (odds ratio = 0.208, 95% confidence interval = 0.121 to 0.358; P < 0.001). After matching, patients receiving PCA demonstrated a significantly lower overall incidence of PPCs (8.6% vs. 26.3%, P < 0.001), unplanned transfer to the intensive care unit (1.1% vs. 8.4%, P = 0.001), and in-hospital mortality (0.7% vs. 5.3%, P = 0.021) compared to those not receiving PCA. No significant difference in outcomes was observed between patients receiving PCIA or PCEA after matching. CONCLUSION: Patient-controlled analgesia, whether administered intravenously or epidurally, is associated with a reduced risk of PPCs in elderly patients undergoing major upper abdominal surgery.

Assessing the impact of enhanced hygiene precautions during the COVID-19 pandemic on surgical site infection risk in abdominal surgeries.

BACKGROUND: A surgical site infection (SSI) is a postoperative infection that occurs at or near the surgical incision. SSIs significantly increase morbidity, mortality, length of hospital stay, and healthcare costs. The World Health Organization (WHO) has established hospital hygiene precaution guidelines for the prevention of SSIs, which were enhanced during the COVID-19 pandemic. The current study aims to explore the effect of the COVID-19 pandemic on SSI incidence among initially uninfected postoperative patients. We hypothesize that these enhanced precautions would reduce the incidence of SSIs. MATERIALS AND METHODS: A retrospective study comparing surgical outcomes before and during the pandemic. Patients who had abdominal surgery between June and December 2019 (Non-COVID-19) or between February and June 2020 (COVID-19) were included. The two groups were matched in a 1:1 ratio based on age, Sex, acuity (elective or emergent), surgical approach, and comorbidities. Electronic medical records were reviewed to identify SSIs and hospital readmissions within 30 days after surgery. Pearson's chi-square test and Fisher's exact test were used. RESULTS: Data was collected and analyzed from 976 patients who had surgery before the COVID-19 pandemic (non-COVID group) and 377 patients who had surgery during the pandemic (COVID group). After matching, there were 377 patients in each group. In our study, we found 23 surgical site infections (SSIs) in both laparoscopic and open surgeries. The incidence of SSIs was significantly higher in the non-COVID period compared to the COVID period [17 cases (4.5%) vs. 6 cases (1.6%), respectively, p = 0.032], especially in non-COVID open surgeries. The incidence of SSIs in laparoscopic surgeries was also higher during the non-COVID period, but not statistically significant. CONCLUSIONS: Enhanced hygiene precautions during the COVID -19 pandemic may have reduced SSIs rates following abdominal surgery.

Alvimopan for postoperative ileus following abdominal surgery: a systematic review.

BACKGROUND: Postoperative ileus (POI) is a common complication following abdominal surgery, often leading to extended hospital stays and a higher risk of post-operative complications, leading to poorer patient outcomes. Alvimopan, a peripherally acting µ-opioid receptor antagonist, has been shown to aid in the recovery of normal bowel function after surgery. While its benefits are well-established in open abdominal surgeries, its efficacy in laparoscopic procedures had not been conclusively determined. However, recent clinical trials involving laparoscopic surgeries have since been conducted. This review aims to reassess the efficacy of Alvimopan by incorporating findings from these new studies, potentially providing further insight into its clinical benefits. METHODS: A comprehensive search of PubMed, Google Scholar, EMBASE, and the Cochrane Library was conducted. Studies were included based on the PICO framework, focusing on Alvimopan's impact on postoperative gastrointestinal recovery. Primary outcomes were time to gastrointestinal function recovery (GI-3) and hospital stay duration. RESULTS: Ten studies met the inclusion criteria, with seven focusing on the use of Alvimopan in open abdominal surgeries and three in laparoscopic procedures. Collectively, these studies involved 18,822 patients undergoing various types of abdominal Administration of Alvimopan 6 mg accelerated gastrointestinal function recovery by an average of 14 h (Hazard ratio: 1.62, p = 0.002) and reduced hospital stays by 5.2 h (Hazard ratio: 1.52, p = 0.04) compared to placebo. Similarly, Alvimopan 12 mg reduced GI-3 recovery time by 13.5 h (Hazard ratio: 1.58, p = 0.02) and hospital stay duration by 6.2 h (Hazard ratio: 1.46, p = 0.018). CONCLUSION: Alvimopan shows promise in reducing POI and hospital stay durations following abdominal surgeries. The incorporation of the recent studies in laparoscopic abdominal procedures further supports these findings. Integrating Alvimopan into perioperative care protocols may enhance patient outcomes and help lower healthcare costs.

Re-examining the classification of abdominal pseudocysts as surgical site infections through review of broad-range polymerase chain reaction results.

BACKGROUND: The Hydrocephalus Clinical Research Network-quality group (HCRNq) historically defined all abdominal pseudocysts associated with a ventriculoperitoneal shunt as a surgical site infection regardless of culture result. METHODS: We retrospectively reviewed broad-range polymerase chain reaction (BRPCR) results sent between January 2017 and July 2023 from abdominal pseudocyst fluid sent from hospitals around the country to a reference laboratory to help further characterize these collections. RESULTS: A total of 19 samples were tested via BRPCR between 1/2017 and 7/2023. Two (10.5 %) had organisms identified; one with Staphylococcus epidermidis and one with Candida parapsilosis. No fastidious organisms that would be expected to not grow with typical culture techniques were identified. CONCLUSIONS: Few abdominal pseudocysts had organisms identified by BRPCR, suggesting that not all pseudocysts are due to infectious causes. Consideration should be given to alternate causes of pseudocyst development when cultures are negative.

Standardization of the strategy for open abdomen in nontrauma emergency laparotomy: A prospective study of outcomes in primary versus temporary abdominal closure.

BACKGROUND: The indications for temporary abdominal closure in nontrauma surgery are heterogeneous and with limited data on clinical outcomes. This study aimed to report the outcomes of primary closure compared with temporary abdominal closure after nontrauma emergency laparotomy within a standardized clinical setting adapted from international guidelines. METHODS: Included were all nontrauma patients undergoing emergency laparotomy between January 1, 2021, and December 31, 2022, at Copenhagen University Hospital Herlev in Denmark. All patients received treatment on the basis of standardized bundle of care trajectory for major emergency abdominal surgery. Mortality, risks of re-laparotomy, and postoperative complications were assessed using Kaplan-Meier plots and multiple logistic regression modeling. RESULTS: Of the 576 included patients, temporary abdominal closure was performed in 57 (10%) patients in the initial surgery. Indications for temporary abdominal closure included damage control strategy as the result of considerable hemodynamic instability in 21 (37%) patients, need for reassessment of bowel viability in 21 (37%) patients, and loss of domain in 15 (25%) patients. Fascial closure was achieved after a median period of 2 days. Sixty-seven patients (12%) underwent re-laparotomy, with temporary abdominal closure performed in 10 (15%) of the cases. Patients with temporary abdominal closure had a significantly greater risk of postoperative complications (odds ratio 2.58, 95% confidence interval 1.38-4.89, P = .003). There were no significant differences in the risks of fascial dehiscence, re-laparotomy, or 30- or 90-days mortality. CONCLUSION: Temporary abdominal closure was performed in 10% of patients undergoing nontrauma emergency laparotomy, with the primary indications being damage control strategy and need for reassessment of bowel viability. Patients undergoing temporary abdominal closure had a significantly greater risk of postoperative complications.

Defining non-inferiority margins in randomised controlled surgical trials: a protocol for a systematic review.

BACKGROUND: The reporting of randomised controlled non-inferiority (NI) drug trials is poor with less than 50% of published trials reporting a justification of the NI margin. This is despite the introduction of the Consolidated Standards of Reporting Trials (CONSORT) extension on reporting of NI and equivalence in randomised trials. It is critical to set the appropriate NI margin as this choice dictates the conclusions of the trial. Methods to estimate the margin are heterogeneous but generally based on clinical judgement and statistical reasoning, and hence tailored to each clinical situation. Yet an appraisal of NI in clinical trials has not been undertaken. Therefore the aim of this systematic review is to assess the reporting and methodological quality of defining the NI margin. Surgical NI trials have been chosen as our prototype to assess this. METHODS: We will conduct a systematic review of published randomised controlled trials in abdominal surgery that use an NI design. Key eligibility criteria will be: surgical intervention in at least one trial arm; adult patients and a sample size of 100 or more. Ovid MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials will be searched from inception until the date of the search. Identified studies will be assessed for reporting according to the CONSORT recommendations. The outcomes are the description of the methods for defining the NI margin, and the robustness of the NI margin estimation. The latter will be based on simulations using alternative assumptions for model parameters. The results of the simulation will be compared with the trial authors' conclusions. ANTICIPATED RESULTS: The review will describe and appraise the design and reporting of surgical NI trials including shortcomings thereof and allow a comparison with pharmaceutical trials. These findings will inform researchers on the appropriate design and pitfalls when conducting surgical randomised controlled trials with an NI design and promote thorough and standardised reporting of study findings. ETHICS AND DISSEMINATION: Ethical approval is not required and any changes to the protocol will be communicated via the registration platform. The final manuscript will be submitted to a journal for publication and the findings will be disseminated through conference presentations to inform researchers and the public.

Illustrated cross-sectional computed tomography of the cetacean abdomino-pelvic organs.

BACKGROUND: Computed tomography (CT) is a non-invasive diagnostic imaging modality which can be used to study the anatomy and morphology of live or deceased animals in-situ. In cetaceans, existing CT anatomy studies mostly focused on the head and thoracic regions. Using postmortem CT (PMCT) scans of Indo-Pacific finless porpoises (Neophocaena phocaenoides), this study describes the cross-sectional imaging anatomy of the cetacean abdomino-pelvic organs for the first time. METHODS: PMCT scans of finless porpoises stranded in Hong Kong waters were reviewed, of which two freshly dead cases, one male and one female, were selected for illustration. In addition, a contrast-enhanced PMCT scan was performed on the female subject as a trial for a PMCT-angiography study (PMCTA) in cetaceans. A total of 18 axial PMCT images were acquired at selected vertebral levels in the abdomen and supplemented with a series of corresponding labeled anatomical diagrams. RESULTS: By applying different image rendering techniques, most osseous and soft tissue structures in the finless porpoise abdomen were successfully depicted and annotated on PMCT, including the male and female reproductive organs in the pelvic region. The application of contrast medium in PMCT created artificial radiodensity differences which improved the ability to visualize and differentiate soft organs and vasculature. The merits and limitations of CT compared to other imaging modalities, as well as the future directions of PMCT in stranding investigation, were discussed. CONCLUSIONS: The findings from this study significantly enhance the applications of CT in cetaceans by assisting researchers and veterinarians in the interpretation of cetacean abdomino-pelvic CT for morphological and pathological assessment during clinical or postmortem examination.

The Use of Narco SS Score in Predicting Adverse Events in Children Undergoing Major Elective Abdominal Surgery at The University Teaching Hospital, Lusaka, Zambia.

BACKGROUND: The neurological, airway, respiratory, cardiovascular and other, with a subscore of surgical severity (NARCO-SS) is a scoring system which assesses the presence of systemic disease and the risk the operation poses to the patient. A number of patients that undergo major abdominal surgery suffer adverse events. The aim of the study was to determine the reliability of NARCO-SS in predicting peri-operative adverse events and to determine the risk factors for peri-operative adverse events in paediatric patients undergoing elective abdominal surgery. MATERIALS AND METHODS: Prospective cohort study. Consecutively sampled patients from December 2019 to December 2020 were used. Patients scheduled for elective abdominal surgery were scored pre-operatively and end points were; when an adverse event occurred or up to day 30. Analysis of the reliability of the tool, bivariate and multivariate logistics regression was done. RESULTS: One hundred and nineteen patients were enrolled and 49% of them had adverse events. Both bivariate and multivariate analyses showed no significant association between the NARCO-SS score and the occurrence of adverse events. The area under the receiver operating characteristics curve (area under the curve) of the NARCO-SS for adverse events was 0.518; there was a significant correlation between high scores and mortality. Longer duration of surgery and complex surgery were the risk factors for adverse events. CONCLUSIONS: The NARCO-SS score was found to be a poor predictor of adverse events with a fair inter-rater reliability as a scoring tool. Future research could evaluate a modification of neurological and airway categories.

An Introduction to Ventra: A Programmable Abdominal Phantom for Training, Educational, Research, and Development Purposes.

BACKGROUND: Intra-abdominal pressure (IAP) is a critical parameter in the care of critically ill patients, as elevated IAP can lead to reduced cardiac output and organ perfusion, potentially resulting in multiple organ dysfunction and failure. The current gold standard for measuring IAP is an indirect technique via the bladder. According to the Abdominal Compartment Society's Guidelines, new measurement methods/devices for IAP must be validated against the gold standard. OBJECTIVES: This study introduces Ventra, an abdominal phantom designed to simulate different IAP levels, abdominal compliance, respiration-related IAP variations, and bladder dynamics. Ventra aims to facilitate the development and validation of new IAP measurement devices while reducing reliance on animal and cadaveric studies. Additionally, it offers potential applications in training and education for biomedical engineering students. This study provides a thorough explanation on the phantom's design and fabrication, which provides a low-cost solution for advancing IAP measurement research and education. The design concept, technical aspects, and a series of validation experiments determining whether Ventra is a suitable tool for future research are presented in this study. METHODS: Ventra's performance was evaluated through a series of validation tests using a pressure gauge and two intra-gastric (Spiegelberg and CiMON) and two intra-bladder (Accuryn and TraumaGuard) pressure measurement devices. The mean and standard deviation of IAP recordings by each device were investigated. Bland-Altman analysis was used to evaluate bias, precision, limits of agreement, and percentage error for each system. Concordance analysis was performed to assess the ability of Ventra in tracking IAP changes. RESULTS: The phantom demonstrated excellent agreement with reference pressure measurements, showing an average bias of 0.11 ± 0.49 mmHg. A concordance coefficient of 100% was observed for the phantom as well. Ventra accurately simulated different abdominal compliances, with higher IAP values resulting in lower compliance. Abdominal volume changes showed a bias of 0.08 ± 0.07 L/min, and bladder fill volume measurements showed an average difference of 0.90 ± 4.33 mL for volumes ranging from 50 to 500 mL. CONCLUSION: The validation results were in agreement with the research guidelines of the world abdominal society. Ventra is a reliable tool that will facilitate the development and validation of new IAP measurement devices. It is an effective educational tool for biomedical engineering students as well.

The Role of Preoperative Abdominal Ultrasound in the Preparation of Patients Undergoing Primary Metabolic and Bariatric Surgery: A Machine Learning Algorithm on 4418 Patients' Records.

BACKGROUND: The utility of preoperative abdominal ultrasonography (US) in evaluating patients with obesity before metabolic bariatric surgery (MBS) remains ambiguously defined. METHOD: Retrospective analysis whereby patients were classified into four groups based on ultrasound results. Group 1 had normal findings. Group 2 had non-significant findings that did not affect the planned procedure. Group 3 required additional or follow-up surgeries without changing the surgical plan. Group 4, impacting the procedure, needed further investigations and was subdivided into 4A, delaying surgery for more assessments, and 4B, altering or canceling the procedure due to critical findings. Machine learning techniques were utilized to identify variables. RESULTS: Four thousand four hundred eighteen patients' records were analyzed. Group 1 was 45.7%. Group 2, 35.7%; Group 3, 17.0%; Group 4, 1.5%, Group 4A, 0.8%; and Group 4B, 0.7%, where surgeries were either canceled (0.3%) or postponed (0.4%). The hyperparameter tuning process identified a Decision Tree classifier with a maximum tree depth of 7 as the most effective model. The model demonstrated high effectiveness in identifying patients who would benefit from preoperative ultrasound before MBS, with training and testing accuracies of 0.983 and 0.985. It also showed high precision (0.954), recall (0.962), F1 score (0.958), and an AUC of 0.976. CONCLUSION: Our study found that preoperative ultrasound demonstrated clinical utility for a subset of patients undergoing metabolic bariatric surgery. Specifically, 15.9% of the cohort benefited from the identification of chronic calculous cholecystitis, leading to concomitant cholecystectomy. Additionally, surgery was postponed in 1.4% of the cases due to other findings. While these findings indicate a potential benefit in certain cases, further research, including a cost-benefit analysis, is necessary to fully evaluate routine preoperative ultrasound's overall utility and economic impact in this patient population.

Incidence and Risk Factors of Surgical Site Infection in Abdominal Surgeries: A Scoping Review of Cohort and Case-Control Studies.

Background: Abdominal surgery is considered a high-risk procedure for the development of surgical site infection (SSI). Few studies have evaluated the relative importance of surgical site infection risk factors in terms of consistency in abdominal surgery. Therefore, this comprehensive review article mapped and summarized the evidence aimed to determine the relative importance of the risk factors and incidence of SSIs in abdominal surgery. Methods: A literature review was conducted using electronic databases and search engines such as Scopus, PubMed, and Web of Science up to March 16, 2023. There was no language restriction for the papers to be included in the study. The relative consistency of the risk factors was measured and evaluated using the methodology of the Joanna Briggs Institute. Original peer-reviewed cohort and case-control studies were included if all types of SSIs were included. Meta-analysis was performed to determine the pooled estimates of SSI incidences. Results: Of 14,237 identified records, 107 articles were included in the review. The pooled incidence of SSI was 10.6% (95% CI: 9.02-12.55%, χ2=12986.44, P<0.001). Operative time and higher wound class were both significant consistent risk factors for SSI incidence. Patients' educational status, malnutrition, functional status, and history of neurological/psychiatric disorders were all candidates for consistent risk factors, with insufficient evidence. Conclusion: The findings of the present study indicated that SSI in abdominal surgery was a multifactorial phenomenon with a considerable risk and had different risk factors with various relative importance. Determining the relative importance of the risk factors for the prevention and control of SSI is strongly recommended.This manuscript has been released as a preprint at the research square: (https://doi.org/10.21203/rs.3.rs-3219597/v1).

Three-dimensional trans-rectal and trans-abdominal ultrasound image fusion for the guidance of gynecologic brachytherapy procedures: a proof of concept study.

High dose-rate brachytherapy is a treatment technique for gynecologic cancers where intracavitary applicators are placed within the patient's pelvic cavity. To ensure accurate radiation delivery, localization of the applicator at the time of insertion is vital. This study proposes a novel method for acquiring, registering, and fusing three-dimensional (3D) trans-abdominal and 3D trans-rectal ultrasound (US) images for visualization of the pelvic anatomy and applicators during gynecologic brachytherapy. The workflow was validated using custom multi-modal pelvic phantoms and demonstrated during two patient procedures. Experiments were performed for three types of intracavitary applicators: ring-and-tandem, ring-and-tandem with interstitial needles, and tandem-and-ovoids. Fused 3D US images were registered to magnetic resonance (MR) and computed tomography (CT) images for validation. The target registration error (TRE) and fiducial localization error (FLE) were calculated to quantify the accuracy of our fusion technique. For both phantom and patient images, TRE and FLE across all modality registrations (3D US versus MR or CT) resulted in mean ± standard deviation of 4.01 ± 1.01 mm and 0.43 ± 0.24 mm, respectively. This work indicates proof of concept for conducting further clinical studies leveraging 3D US imaging as an accurate, accessible alternative to advanced modalities for localizing brachytherapy applicators.

Fast prediction of personalized abdominal organ doses from CT examinations by radiomics feature-based machine learning models.

The X-rays emitted during CT scans can increase solid cancer risks by damaging DNA, with the risk tied to patient-specific organ doses. This study aims to establish a new method to predict patient specific abdominal organ doses from CT examinations using minimized computational resources at a fast speed. The CT data of 247 abdominal patients were selected and exported to the auto-segmentation software named DeepViewer to generate abdominal regions of interest (ROIs). Radiomics feature were extracted based on the selected CT data and ROIs. Reference organ doses were obtained by GPU-based Monte Carlo simulations. The support vector regression (SVR) model was trained based on the radiomics features and reference organ doses to predict abdominal organ doses from CT examinations. The prediction performance of the SVR model was tested and verified by changing the abdominal patients of the train and test sets randomly. For the abdominal organs, the maximal difference between the reference and the predicted dose was less than 1 mGy. For the body and bowel, the organ doses were predicted with a percentage error of less than 5.2%, and the coefficient of determination (R2) reached up to 0.9. For the left kidney, right kidney, liver, and spinal cord, the mean absolute percentage error ranged from 5.1 to 8.9%, and the R2 values were more than 0.74. The SVR model could be trained to achieve accurate prediction of personalized abdominal organ doses in less than one second using a single CPU core.

An inventory of patient-image based risk/dose, image quality and body habitus/size metrics for adult abdomino-pelvic CT protocol optimisation.

PURPOSE: Patient-specific protocol optimisation in abdomino-pelvic Computed Tomography (CT) requires measurement of body habitus/size (BH), sensitivity-specificity (surrogates image quality (IQ) metrics) and risk (surrogates often dose quantities) (RD). This work provides an updated inventory of metrics available for each of these three categories of optimisation variables derivable directly from patient measurements or images. We consider objective IQ metrics mostly in the spatial domain (i.e., those related directly to sharpness, contrast, noise quantity/texture and perceived detectability as these are used by radiologists to assess the acceptability or otherwise of patient images in practice). MATERIALS AND METHODS: The search engine used was PubMed with the search period being 2010-2024. The key words used were: 'comput* tomography', 'CT', 'abdom*', 'dose', 'risk', 'SSDE', 'image quality', 'water equivalent diameter', 'size', 'body composition', 'habit*', 'BMI', 'obes*', 'overweight'. Since BH is critical for patient specific optimisation, articles correlating RD vs BH, and IQ vs BH were reviewed. RESULTS: The inventory includes 11 BH, 12 IQ and 6 RD metrics. 25 RD vs BH correlation studies and 9 IQ vs BH correlation studies were identified. 7 articles in the latter group correlated metrics from all three categories concurrently. CONCLUSIONS: Protocol optimisation should be fine-tuned to the level of the individual patient and particular clinical query. This would require a judicious choice of metrics from each of the three categories. It is suggested that, for increased utility in clinical practice, more future optimisation studies be clinical task based and involve the three categories of metrics concurrently.