Haemorrhoid artery ligation - recto anal repair (HAL-RAR) blind versus Doppler: a systematic review and meta-analysis.

BACKGROUND: Haemorrhoids remain a highly prevalent condition in Australia, affecting 39% of the adult Australian population. While haemorrhoidectomy remains the gold standard in the management of haemorrhoids, newer techniques such as haemorrhoid artery ligation-recto anal repair (HAL-RAR) are emerging as promising management modalities. We compare the efficacy of non-Doppler guided (non-DG) HAL-RAR versus Doppler-guided (DG) HAL-RAR in the management of haemorrhoids. METHODS: This study was registered with PROSPERO (CRD42022353806) and adhered to PRISMA 2020 guidelines. We conducted a systematic review using Medline, Embase and Cochrane database for comparative studies between Doppler-guided HAL-RAR and non-Doppler-guided HAL-RAR in accordance with the PRISMA 2020 statement for reporting systematic reviews. RESULTS: Five studies were included in our systematic review and meta-analysis. There was no clinically significant difference in operative times (SMD 0.46, 9% CI -3.16 0 4.08, P = 0.804) or post-operative bleeding (P = 0.142) between the two groups. DG HAL-RAR patients were more likely to have post-operative urinary retention (P < 0.001). Non-DG patients were less likely to experience recurrence (OR 5.12, P < 0.001). CONCLUSION: Our review of non-DG HAL-RAR compared to DG HAL-RAR reflects the non-inferiority of the non-DG HALRAR procedure. We hope that these results would provide a guide to clinicians performing HAL-RAR, and would provide some cost savings for institutions who are unable to procure the necessary equipment for DG HAL-RAR.

Applications of natural language processing tools in the surgical journey.

Background: Natural language processing tools are becoming increasingly adopted in multiple industries worldwide. They have shown promising results however their use in the field of surgery is under-recognised. Many trials have assessed these benefits in small settings with promising results before large scale adoption can be considered in surgery. This study aims to review the current research and insights into the potential for implementation of natural language processing tools into surgery. Methods: A narrative review was conducted following a computer-assisted literature search on Medline, EMBASE and Google Scholar databases. Papers related to natural language processing tools and consideration into their use for surgery were considered. Results: Current applications of natural language processing tools within surgery are limited. From the literature, there is evidence of potential improvement in surgical capability and service delivery, such as through the use of these technologies to streamline processes including surgical triaging, data collection and auditing, surgical communication and documentation. Additionally, there is potential to extend these capabilities to surgical academia to improve processes in surgical research and allow innovation in the development of educational resources. Despite these outcomes, the evidence to support these findings are challenged by small sample sizes with limited applicability to broader settings. Conclusion: With the increasing adoption of natural language processing technology, such as in popular forms like ChatGPT, there has been increasing research in the use of these tools within surgery to improve surgical workflow and efficiency. This review highlights multifaceted applications of natural language processing within surgery, albeit with clear limitations due to the infancy of the infrastructure available to leverage these technologies. There remains room for more rigorous research into broader capability of natural language processing technology within the field of surgery and the need for cross-sectoral collaboration to understand the ways in which these algorithms can best be integrated.

A systematic review of minimally invasive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with peritoneal malignancy.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is traditionally a maximally invasive operation with a large abdominal incision and multi-visceral resections. However, to minimize abdominal wall morbidity and improve functional recovery, some centres have adopted a minimally invasive (MI) approach in select cases. The primary aim of this systematic review and meta-analysis was to assess the evidence for safety and patient selection for minimally invasive approaches to CRS and HIPEC with curative intent. METHODS: A PRISMA-compliant systematic review was performed using three electronic databases: Ovid MEDLINE, EMBASE and Web of Science. Data regarding postoperative morbidity was meta-analysed. RESULTS: Thirteen studies met the inclusion criteria (N = 462 MI patients), all of which were retrospective in design. Six studies included an open comparison group. Pseudomyxoma peritonei, mesothelioma and ovarian carcinoma made up the majority of cases (>90%), with a PCI < 10 listed as a prerequisite to selection across all studies. On pooled analysis there was no difference in major morbidity between MI and open groups (OR 0.52 95% CI 0.18-1.46, P = 0.33). There was one perioperative death reported in the MI group. Length of stay appeared shorter in the MI group (median range MI: 4-11 v Open: 7-13 days). Short-term recurrence and overall survival between both groups also appeared no different. CONCLUSION: Minimally invasive CRS and HIPEC appears feasible and safe in appropriately selected patients. Clear histological stratification and longer term follow up is required to determine oncological safety, particularly in more aggressive tumours such as colorectal peritoneal metastases.

Emerging multi-port soft tissue robotic systems: a systematic review of clinical outcomes.

Multiple novel multi-port robotic surgical systems have been introduced into clinical practice. This systematic review aims to evaluate the clinical outcomes of these novel robotic systems to conventional laparoscopic technique and established da Vinci robotic surgical platforms. A literature search of Embase, Medline, Pubmed, Cochrane library, and Google Scholar was performed according to the PRISMA guidelines from 2012 to May 2023. Studies comparing clinical outcomes of novel multi-port robotic surgical systems with laparoscopic or the da Vinci platforms were included. Case series with no comparison groups were excluded. Descriptive statistics were used to report patient and outcome data. A systematic narrative review was provided for each outcome. Twelve studies comprised of 1142 patients were included. A total of 6 novel multi-port robotic systems: Micro Hand S, Senhance, Revo-i MSR-5000, KangDuo, Versius, and Hugo™ RAS were compared against the laparoscopic or the da Vinci robotic platforms. Clinical outcomes of these novel robotic platforms were comparable to the established da Vinci platforms. When compared against conventional laparoscopic approaches, the robotic platforms demonstrated lower volume of blood loss, shorter length of stay but longer operative time. This systematic review highlighted the safe implementation and efficacy of 6 new robotic systems. The clinical outcomes achieved by these new robotic systems are comparable to the established da Vinci robotic system in simple to moderate case complexities. There is emerging evidence that these new robotic systems provide a viable alternative to currently available robotic platforms.

Robotic versus laparoscopic gastric bypass in bariatric surgery: a systematic review and meta-analysis on perioperative outcomes.

BACKGROUND: Robotic-assisted surgery has emerged as a compelling approach to bariatric surgery. However, current literature has not consistently demonstrated superior outcomes to laparoscopic bariatric surgery to justify its higher cost. With its mechanical advantages, the potential gains from the robotic surgical platform are likely to be apparent in more complex cases such as gastric bypass, especially revisional cases. OBJECTIVE: This systematic review and meta-analysis aimed to summarize the literature and evaluate the peri-operative outcomes of patients with obesity undergoing robotic gastric bypass versus laparoscopic gastric bypass surgery. SETTING: Systematic review. METHODS: A literature search of Embase, Medline, Pubmed, Cochrane library, and Google Scholar was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies comparing outcomes of robotic and laparoscopic gastric bypass for obesity were included. RESULTS: Twenty-eight eligible studies comprised a total of 82,155 patients; 9051 robotic bypass surgery (RBS) versus 73,104 laparoscopic bypass surgery (LBS) were included. All included studies compared Roux-en-Y gastric bypass. RBS was noted to have higher reoperation rate within 30 days (4.4% versus 3.4%; odds ratio 1.31 [95% CI, 1.04-1.66]; P = .027; I2 = 43.5%) than LBS. All other endpoints measured (complication rate, anastomotic leak, anastomotic stricture, surgical site infections, hospital readmission, length of stay, operative time, conversion rate and mortality) did not show any difference between RBS and LBS. CONCLUSION: This systematic review and meta-analysis showed that there was no significant difference in key outcome measures in robotic versus laparoscopic gastric bypass. RBS was associated with a slightly higher reoperation rate and there was no reduction in overall complication rate with the use of robotic platform.

Use of patient-derived explants as a preclinical model for precision medicine in colorectal cancer: A scoping review.

PURPOSE: Whilst the treatment paradigm for colorectal cancer has evolved significantly over time, there is still a lack of reliable biomarkers of treatment response. Treatment decisions are based on high-risk features such as advanced TNM stage and histology. The role of the tumour microenvironment, which can influence tumour progression and treatment response, has generated considerable interest. Patient-derived explant cultures allow preservation of native tissue architecture and tumour microenvironment. The aim of the scoping review is to evaluate the utility of patient-derived explant cultures as a preclinical model in colorectal cancer. METHODS: A search was conducted using Ovid MEDLINE, EMBASE, Web of Science, and Cochrane databases from start of database records to September 1, 2022. We included all peer-reviewed human studies in English language which used patient-derived explants as a preclinical model in primary colorectal cancer. Eligible studies were grouped into the following categories: assessing model feasibility; exploring tumour microenvironment; assessing ex vivo drug responses; discovering and validating biomarkers. RESULTS: A total of 60 studies were eligible. Fourteen studies demonstrated feasibility of using patient-derived explants as a preclinical model. Ten studies explored the tumour microenvironment. Thirty-eight studies assessed ex vivo drug responses of chemotherapy agents and targeted therapies. Twenty-four studies identified potential biomarkers of treatment response. CONCLUSIONS: Given the preservation of tumour microenvironment and tumour heterogeneity, patient-derived explants has the potential to identify reliable biomarkers, treatment resistance mechanisms, and novel therapeutic agents. Further validation studies are required to characterise, refine and standardise this preclinical model before it can become a part of precision medicine in colorectal cancer.

Association of change in fat and lean mass with incident cardiovascular events for women in midlife and beyond: A prospective study using dual-energy x-ray absorptiometry (DXA).

OBJECTIVE: To determine whether changes in fat and lean mass over time, quantified using dual-energy x-ray absorptiometry (DXA), are related to incident cardiovascular events. Previous studies using surrogate anthropometric methods have had inconsistent findings. STUDY DESIGN: Prospective, longitudinal observational study of women aged 40 to 80 randomly selected from the electoral roll and stratified into decades: 40-49, 50-59, 60-69 and 70-79 years. MAIN OUTCOME MEASURES: Changes in anthropometric measurements (body mass index and waist-to-hip ratio) and DXA-quantified fat mass and lean mass between the first and fifth years of the study. Incident cardiovascular events recorded from the sixth to the 12th year. RESULTS: In total 449 participants (87.9 %) were analyzed. A 10 % or greater decrease in total fat mass index was associated with a 67 % lower likelihood of any cardiovascular event (OR = 0.33, 95%CI 0.15-0.71); no association was observed for an increase. A 10 % or greater decrease in abdominal fat mass index was associated with a 62 % lower likelihood of incident stroke (OR = 0.38, 95%CI 0.16-0.91); no association was observed for an increase. A 10 % or greater decrease in appendicular lean mass index resulted in increased odds ratio of 2.91 for incident peripheral artery events (OR = 2.91, 95%CI 1.18-7.20). CONCLUSIONS: Reducing fat mass for women in midlife and beyond may decrease the risk of cardiovascular events. An increase in fat mass may not contribute to additional cardiovascular events. A reduction in limb muscle mass may provide an independent marker for cardiometabolic risk and peripheral artery disease. No independent association was found using anthropometric measurements and incident cardiovascular events.

Analytical expressions for spreading resistance in lossy media and their application to the calibration of scanning microwave microscopy.

This paper presents the analytical derivation of spreading resistance expressions for diverse geometries of a conducting probe submerged in a lossy medium. Resulting equations can be used to calibrate scanning impedance/scanning microwave microscopes operating in liquid. The expressions are systematically validated through numerical and experimental methods for the calibration of an inverted Scanning Microwave Microscope (iSMM) when operating in a lossy saline medium, such as Dulbecco's Modified Eagle Medium (DMEM), a widely used medium for supporting the growth of biological cells. The calibration process within DMEM plays an important role in the quantitative local evaluation of electromagnetic properties of biological samples under physiological conditions. Additionally, measurements are performed in distilled water for comparative analysis.

Immune mediated colitis: a surgical perspective.

BACKGROUND: This study aims to review and summarize the current up to date literature that explore the current treatment approaches to immune mediated colitis and the role of surgical specialties in the landscape of management. METHODS: A narrative review of papers was performed following a literature search through Medline, EMBASE and Cochrane Central databases pertaining to immune mediated colitis as an adverse event of cancer immunotherapy. RESULTS: Current guidelines for the diagnosis and treatment of immune mediated colitis mirror the approach to the workup of inflammatory bowel disease and guided by treating oncology and gastroenterology specialties. Immune mediated colitis however relies on surgical specific skills as a consequence of obtaining a diagnosis as well as in the management of complications that may arise. CONCLUSION: Immune mediate colitis management has largely been under the purview of medical specialties. This review explores the current landscape of managing immune mediated colitis from a surgical perspective and highlights key areas in which surgeons can engage in the multidisciplinary care of this condition. To facilitate prompt diagnosis and management of immune-mediated colitis, there is an increasing necessity for surgeons to become familiar with the latest multidisciplinary approaches and recommendations.

Fabrication of Ultra-Sharp Tips by Dynamic Chemical Etching Process for Scanning Near-Field Microwave Microscopy.

This work details an effective dynamic chemical etching technique to fabricate ultra-sharp tips for Scanning Near-Field Microwave Microscopy (SNMM). The protruded cylindrical part of the inner conductor in a commercial SMA (Sub Miniature A) coaxial connector is tapered by a dynamic chemical etching process using ferric chloride. The technique is optimized to fabricate ultra-sharp probe tips with controllable shapes and tapered down to have a radius of tip apex around ∼1 µm. The detailed optimization facilitated the fabrication of reproducible high-quality probes suitable for non-contact SNMM operation. A simple analytical model is also presented to better describe the dynamics of the tip formation. The near-field characteristics of the tips are evaluated by finite element method (FEM) based electromagnetic simulations and the performance of the probes has been validated experimentally by means of imaging a metal-dielectric sample using the in-house scanning near-field microwave microscopy system.

Retrospective audit: Utility of PET scan in routine preoperative rectal cancer staging.

BACKGROUND: Accurate staging for rectal cancer is pertinent with recent introduction of rectum-sparing approaches for patients showing complete clinical response on restaging. Positron emission tomography(PET) is used in detection of recurrence or metastasis, but its value in routine preoperative rectal cancer staging remains unclear. Studies report that preoperative PET altered the stage in 39% and changed the management in 17-27% of patients. Our study aims to look at the utility of PET in routine preoperative staging of rectal cancer within 2 two colorectal units, and to determine if PET did result in a change in management. METHODS: Patients in Nepean Hospital (NSW) and Peter MacCallum Cancer Centre (VIC) who were diagnosed with rectal cancer between 1 January 2017 and 31 December 2021 were included in this retrospective study. All patients who did not have a PET scan were excluded. PET scan results were then compared with MRI and CT results. RESULTS: Three hundred and fifty-seven patients were included in the study. 30.3% of the patients had Stage 3 rectal cancer. 71.7% received neoadjuvant therapy. PET scan provided additional information in 55.5% of patients when compared with CT and MRI alone; 18.2% of the PET findings resulted in an altered management for the patient. CONCLUSION: PET scan can be a valuable tool in accurate staging, especially for ambiguous or equivocal lesions on CT. Our study demonstrated that additional information from PET scan resulted in an altered management plan in 18.2% of the patients. PET/MRI as a newer modality may be more accurate with reduced radiation exposure.

Operative and oncological outcomes after robotic rectal resection compared with laparoscopy: a systematic review and meta-analysis.

BACKGROUND: Most studies comparing robotic and laparoscopic surgery, show little difference in clinical outcomes to justify the expense. We systematically reviewed and pooled evidence from studies comparing robotic and laparoscopic rectal resection. METHOD: Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica (EMBASE), and Cochrane databases were searched for studies between 1996 and 2021 comparing clinical outcomes between laparoscopic and robotic rectal surgeries involving total mesorectal excision. Outcome measures included operative times, conversions to open, complications, recurrence and survival rates. RESULTS: Fifty eligible studies compared outcomes between robotic and laparoscopic rectal resections; three were randomized trials. Pooled results showed significantly longer operating times for robotic surgery but lower conversion and complications rates, shorter lengths of stay in hospital, better rates of complete mesorectal resection and better three-year overall survival. However, the low number of randomized studies makes most data subject to bias. CONCLUSION: Available evidence supports the safety and ongoing use of robotic rectal cancer surgery, while further high-quality evidence is sought to justify the expense.

Nanoscale Characterization of Graphene Oxide-Based Epoxy Nanocomposite Using Inverted Scanning Microwave Microscopy.

Scanning microwave microscopy (SMM) is a novel metrological tool that advances the quantitative, nanometric, high-frequency, electrical characterization of a broad range of materials of technological importance. In this work, we report an inverted near-field scanning microwave microscopy (iSMM) investigation of a graphene oxide-based epoxy nanocomposite material at a nanoscopic level. The high-resolution spatial mapping of local conductance provides a quantitative analysis of the sample's electrical properties. In particular, the electrical conductivity in the order of ∼10-1 S/m as well as the mapping of the dielectric constant with a value of ∼4.7 ± 0.2 are reported and validated by the full-wave electromagnetic modeling of the tip-sample interaction.

Effect of Surgical Humidification on Inflammation and Peritoneal Trauma in Colorectal Cancer Surgery: A Randomized Controlled Trial.

BACKGROUND: Pre-clinical studies indicate that dry-cold-carbon-dioxide (DC-CO2) insufflation leads to more peritoneal damage, inflammation and hypothermia compared with humidified-warm-CO2 (HW-CO2). Peritoneum and core temperature in patients undergoing colorectal cancer (CRC) surgery were compared. METHODS: Sixty-six patients were randomized into laparoscopic groups; those insufflated with DC-CO2 or HW-CO2. A separate group of nineteen patients undergoing laparotomy were randomised to conventional surgery or with the insertion of a device delivering HW-CO2. Temperatures were monitored and peritoneal biopsies and bloods were taken at the start of surgery, at 1 and 3 h. Further bloods were taken depending upon hospital length-of-stay (LOS). Peritoneal samples were subjected to scanning electron microscopy to evaluate mesothelial damage. RESULTS: Laparoscopic cases experienced a temperature drop despite Bair-HuggerTM use. HW-CO2 restored normothermia (≥ 36.5 °C) by 3 h, DC-CO2 did not. LOS was shorter for colon compared with rectal cancer cases and if insufflated with HW-CO2 compared with DC-CO2; 5.0 vs 7.2 days, colon and 11.6 vs 15.4 days rectum, respectively. Unexpectedly, one third of patients had pre-existing damage. Damage increased at 1 and 3 h to a greater extent in the DC-CO2 compared with the HW-CO2 laparoscopic cohort. C-reactive protein levels were higher in open than laparoscopic cases and lower in both matched HW-CO2 groups. CONCLUSIONS: This prospective RCT is in accord with animal studies while highlighting pre-existing damage in some patients. Peritoneal mesothelium protection, reduced inflammation and restoration of core-body temperature data suggest benefit with the use of HW-CO2 in patients undergoing CRC surgery.