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.
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.
BACKGROUND: 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.

We present a case of a 31-year-old male who presented to the emergency department with a history of abdominal pain localized to the lower abdomen. The patient had undergone splenectomy 2 years ago for splenic injury following a road traffic accident. Computerized tomography showed multiple well-defined, homogeneously enhancing soft tissue density nodules of varying sizes distributed throughout the abdomen and pelvis. A diagnosis of splenosis was made based on imaging findings and history. Abdominal splenosis is an uncommon entity of which radiologists need to be aware, and this case serves to shed further light on this condition.

BACKGROUND: Abdominal adhesions represent a chronic postsurgical disease without reliable prophylaxis. Animal modeling has been a cornerstone of novel therapeutic development but has not produced reliable clinical therapies for prevention of adhesive small bowel obstruction. The purpose of this scoping review is to analyze animal models for abdominal adhesion generation by key considerations of external validity (i.e., fidelity, homology, and discrimination).
METHODS: A literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews Extension for Scoping Reviews guidelines. Peer-reviewed publications were included that described the development or quality assessment of experimental animal models for abdominal adhesions with inclusion of a scoring system. Studies that focused on treatment evaluation, implantation of surgical devices, models of nonsurgical etiologies for abdominal adhesions, non-in vivo modeling, and investigations involving human subjects were excluded.
RESULTS: Four hundred and fifteen (n = 415) articles were identified by prespecified search criteria. Of these, 13 studies were included for review.
CONCLUSIONS: Translation of investigational therapeutics for abdominal adhesion prevention is dependent upon high-quality experimental animal models that reproduce the clinical adhesions seen in the operating room as a disease of the entire abdomen.

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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).

Malnutrition plays a crucial role as a risk factor in patients undergoing major abdominal surgery. To mitigate the risk of complications, nutritional prehabilitation has been recommended for malnourished patients and those at severe metabolic risk. Various approaches have been devised, ranging from traditional short-term conditioning lasting 7-14 days to longer periods integrated into a comprehensive multimodal prehabilitation program. However, a significant challenge is the considerable heterogeneity of nutritional interventions, leading to a lack of clear, synthesizable evidence for specific dietary recommendations. This narrative review aims to outline the concept of nutritional prehabilitation, offers practical recommendations for clinical implementation, and also highlights the barriers and facilitators involved.

OBJECTIVE: This systematic review aimed to compare the effect of contrast media (CM) dose adjustment based on lean body weight (LBW) method versus other calculation protocols for abdominopelvic CT examinations.
METHODS: Studies published from 2002 onwards were systematically searched in June 2024 across Medline, Embase, CINAHL, Cochrane CENTRAL, Web of Science, Google Scholar and four other grey literature sources, with no language limit. Randomised controlled trials (RCT) and quasi-RCT of abdominopelvic or abdominal CT examinations in adults with contrast media injection for oncological and acute diseases were included. The comparators were other contrast dose calculation methods such as total body weight (TBW), fixed volume (FV), body surface area (BSA), and blood volume. The main outcomes considered were liver and aortic enhancement. Titles, abstracts and full texts were independently screened by two reviewers.
RESULTS: Eight studies were included from a total of 2029 articles identified. Liver parenchyma and aorta contrast enhancement did not significantly differ between LBW and TBW protocols (p = 0.07, p = 0.06, respectively). However, the meta-analysis revealed significantly lower contrast volume injected with LBW protocol when compared to TBW protocol (p = 0.003). No statistical differences were found for contrast enhancement and contrast volume between LBW and the other strategies.
CONCLUSIONS: Calculation of the CM dosage based on LBW allows a reduction in the injected volume for abdominopelvic CT examination, ensuring the same image quality in terms of contrast enhancement.

Spinal anesthesia is a common anesthetic technique for lower limb and abdominal surgery. Despite its efficacy, its use is limited because of its duration and potential severe side effects, especially in high-risk patients undergoing major surgery. Adjuvants such as dexamethasone offer the potential to prolong the anesthetic effect and reduce the need for local anesthetics while reducing the incidence of serious adverse events. The purpose of this systematic review is to evaluate the efficacy of dexamethasone as an intrathecal adjuvant in prolonging anesthetic duration, delaying pain onset, and minimizing adverse events (PROSPERO registration: CRD42022350218).
We included randomized controlled trials conducted in adult patients undergoing spinal anesthesia for lower limb or abdominal surgery and comparing the performance of dexamethasone with alternative spinal treatments. A comprehensive systematic search was conducted on PubMed/MEDLINE, Scopus, CINAHL, EMBASE, CENTRAL, and Cochrane Library from February to June 2023 without language restriction. Risk of bias was assessed using the Cochrane Risk of Bias Tool (RoB2).
Ten studies, nine of which were at high risk of bias, were included (N.=685 patients). Overall, intrathecal dexamethasone was associated with a longer duration of sensory block, improvement in the duration or extent of postoperative analgesia, and significant shortening of block onset. The role of dexamethasone in prolonging motor block was not clear. The incidence of adverse events was low. Intrathecal dexamethasone has been shown to be a potentially valuable adjuvant to prolong the duration of sensory block and improve postoperative analgesia without increasing adverse events.
Given the wide heterogeneity of methodological approaches, further investigation is needed. Considering the limitations of the included studies and awaiting more conclusive evidence, the prudent use of dexamethasone could be recommended in those specific situations where general anesthesia or higher local anesthetics should be avoided.

The impact of multimodal prehabilitation on postoperative complications in upper abdominal surgeries is understudied. This review analyzes randomized trials on multimodal prehabilitation with patient and hospital outcomes. MEDLINE, Embase, CINAHL, and Cochrane CENTRAL were searched for trials on prehabilitation before elective (non-emergency) abdominal surgery. Two reviewers independently screened studies, extracted data, and assessed study quality. Primary outcomes of interest were postoperative pulmonary complications (PPCs) and all-cause complications; secondary outcomes included hospital and intensive care length of stay. A meta-analysis with random-effect models was performed, and heterogeneity was evaluated with I-square and Cochran\'s Q test. Dichotomous variables were reported in log-odds ratio and continuous variables were presented as mean difference. Ten studies (total 1503 patients) were included. Odds of developing complications after prehabilitation were significantly lower compared to various control groups (- 0.38 [- 0.75- - 0.004], P = 0.048). Five studies described PPCs, and participants with prehabilitation had decreased odds of PPC (- 0.96 [- 1.38- - 0.54], P < 0.001). Prehabilitation did not significantly reduce length of stay, unless exercise was implemented; with exercise, hospital stay decreased significantly (- 0.91 [- 1.67- - 0.14], P = 0.02). Multimodal prehabilitation may decrease complications in upper abdominal surgery, but not necessarily length of stay; research should address heterogeneity in the literature.

BACKGROUND: To evaluate outcomes of low with high intraabdominal pressure during laparoscopic colorectal resection surgery.
METHODS: A systematic search of multiple electronic data sources was conducted, and all studies comparing low with high (standard) intraabdominal pressures were included. Our primary outcomes were post-operative ileus occurrence and return of bowel movement/flatus. The evaluated secondary outcomes included: total operative time, post-operative haemorrhage, anastomotic leak, pneumonia, surgical site infection, overall post-operative complications (categorised by Clavien-Dindo grading), and length of hospital stay. Revman 5.4 was used for data analysis.
RESULTS: Six randomised controlled trials (RCTs) and one observational study with a total of 771 patients (370 surgery at low intraabdominal pressure and 401 at high pressures) were included. There was no statistically significant difference in all the measured outcomes; post-operative ileus [OR 0.80; CI (0.42, 1.52), P = 0.50], time-to-pass flatus [OR -4.31; CI (-12.12, 3.50), P = 0.28], total operative time [OR 0.40; CI (-10.19, 11.00), P = 0.94], post-operative haemorrhage [OR 1.51; CI (0.41, 5.58, P = 0.53], anastomotic leak [OR 1.14; CI (0.26, 4.91), P = 0.86], pneumonia [OR 1.15; CI (0.22, 6.09), P = 0.87], SSI [OR 0.69; CI (0.19, 2.47), P = 0.57], overall post-operative complications [OR 0.82; CI (0.52, 1.30), P = 0.40], Clavien-Dindo grade ≥ 3 [OR 1.27; CI (0.59, 2.77), P = 0.54], and length of hospital stay [OR -0.68; CI (-1.61, 0.24), P = 0.15].
CONCLUSIONS: Low intraabdominal pressure is safe and feasible approach to laparoscopic colorectal resection surgery with non-inferior outcomes to standard or high pressures. More robust and well-powered RCTs are needed to consolidate the potential benefits of low over high pressure intra-abdominal surgery.