Evaluating the Impact of Enhanced Recovery After Surgery Protocols on Surgical Outcomes Following Bariatric Surgery-A Systematic Review and Meta-analysis of Randomised Clinical Trials.

BACKGROUND: Enhanced recovery after surgery (ERAS) programmes are evidence-based care improvement processes for surgical patients, which are designed to decrease the impact the anticipated negative physiological cascades following surgery. AIM: To perform a systematic review and meta-analysis of randomised clinical trials (RCTs) to evaluate the impact of ERAS protocols on outcomes following bariatric surgery compared to standard care (SC). METHODS: A systematic review was performed in accordance with PRISMA guidelines. Meta-analysis was performed using Review Manager version 5.4 RESULTS: Six RCTs including 740 patients were included. The mean age was 40.2 years, and mean body mass index was 44.1 kg/m2. Overall, 54.1% underwent Roux-en-Y gastric bypass surgery (400/740) and 45.9% sleeve gastrectomy (340/700). Overall, patients randomised to ERAS programmes had a significant reduction in nausea and vomiting (odds ratio (OR): 0.42, 95% confidence interval (CI): 0.19-0.95, P = 0.040), intraoperative time (mean difference (MD): 5.40, 95% CI: 3.05-7.77, P < 0.001), time to mobilisation (MD: - 7.78, 95% CI: - 5.46 to - 2.10, P < 0.001), intensive care unit stay (ICUS) (MD: 0.70, 95% CI: 0.13-1.27, P = 0.020), total hospital stay (THS) (MD: - 0.42, 95% CI: - 0.69 to - 0.16, P = 0.002), and functional hospital stay (FHS) (MD: - 0.60, 95% CI: - 0.98 to - 0.22, P = 0.002) compared to those who received SC. CONCLUSION: ERAS programmes reduce postoperative nausea and vomiting, intraoperative time, time to mobilisation, ICUS, THS, and FHS compared to those who received SC. Accordingly, ERAS should be implemented, where feasible, for patients indicated to undergo bariatric surgery. Trial registration International Prospective Register of Systematic Reviews (PROSPERO - CRD42023434492.

Evaluating mesh fixation techniques for ventral hernia repair: A systematic review and network meta-analysis of randomised control trials.

INTRODUCTION: There is uncertainty regarding the optimal mesh fixation techniques for laparoscopic ventral and incisional hernia repair. AIM: To perform a systematic review and network meta-analysis of randomised control trials (RCTs) to investigate the advantages and disadvantages associated with absorbable tacks, non-absorbable tacks, non-absorbable sutures, non-absorbable staples, absorbable synthetic glue, absorbable sutures and non-absorbable tacks, and non-absorbable sutures and non-absorbable tacks. METHODS: A systematic review was performed as per PRISMA-NMA guidelines. Odds ratios (ORs) and mean differences (MDs) were extracted to compare the efficacy of the surgical approaches. RESULTS: Nine RCTs were included with 707 patients. Short-term pain was significantly reduced in non-absorbable staples (MD; -1.56, confidence interval (CI); -2.93 to -0.19) and non-absorbable sutures (MD; -1.00, CI; -1.60 to -0.40) relative to absorbable tacks. Recurrence, length of stay, operative time, conversion to open surgery, seroma and haematoma formation were unaffected by mesh fixation technique. CONCLUSION: Short-term post-operative pain maybe reduced by the use of non-absorbable sutures and non-absorbable staples. There is clinical equipoise between each modality in relation to recurrence, length of stay, and operative time.

Redo Pelvic Surgery and Combined Metastectomy for Locally Recurrent Rectal Cancer with Known Oligometastatic Disease: A Multicentre Review.

INTRODUCTION: Historically, surgical resection for patients with locally recurrent rectal cancer (LRRC) had been reserved for those without metastatic disease. 'Selective' patients with limited oligometastatic disease (OMD) (involving the liver and/or lung) are now increasingly being considered for resection, with favourable five-year survival rates. METHODS: A retrospective analysis of consecutive patients undergoing multi-visceral pelvic resection of LRRC with their oligometastatic disease between 1 January 2015 and 31 August 2021 across four centres worldwide was performed. The data collected included disease characteristics, neoadjuvant therapy details, perioperative and oncological outcomes. RESULTS: Fourteen participants with a mean age of 59 years were included. There was a female preponderance (n = 9). Nine patients had liver metastases, four had lung metastases and one had both lung and liver disease. The mean number of metastatic tumours was 1.5 +/- 0.85. R0 margins were obtained in 71.4% (n = 10) and 100% (n = 14) of pelvic exenteration and oligometastatic disease surgeries, respectively. Mean lymph node yield was 11.6 +/- 6.9 nodes, with positive nodes being found in 28.6% (n = 4) of cases. A single major morbidity was reported, with no perioperative deaths. At follow-up, the median disease-free survival and overall survival were 12.3 months (IQR 4.5-17.5 months) and 25.9 months (IQR 6.2-39.7 months), respectively. CONCLUSIONS: Performing radical multi-visceral surgery for LRRC and distant oligometastatic disease appears to be feasible in appropriately selected patients that underwent good perioperative counselling.

Clinical application of machine learning and computer vision to indocyanine green quantification for dynamic intraoperative tissue characterisation: how to do it.

INTRODUCTION: Indocyanine green (ICG) quantification and assessment by machine learning (ML) could discriminate tissue types through perfusion characterisation, including delineation of malignancy. Here, we detail the important challenges overcome before effective clinical validation of such capability in a prospective patient series of quantitative fluorescence angiograms regarding primary and secondary colorectal neoplasia. METHODS: ICG perfusion videos from 50 patients (37 with benign (13) and malignant (24) rectal tumours and 13 with colorectal liver metastases) of between 2- and 15-min duration following intravenously administered ICG were formally studied (clinicaltrials.gov: NCT04220242). Video quality with respect to interpretative ML reliability was studied observing practical, technical and technological aspects of fluorescence signal acquisition. Investigated parameters included ICG dosing and administration, distance-intensity fluorescent signal variation, tissue and camera movement (including real-time camera tracking) as well as sampling issues with user-selected digital tissue biopsy. Attenuating strategies for the identified problems were developed, applied and evaluated. ML methods to classify extracted data, including datasets with interrupted time-series lengths with inference simulated data were also evaluated. RESULTS: Definable, remediable challenges arose across both rectal and liver cohorts. Varying ICG dose by tissue type was identified as an important feature of real-time fluorescence quantification. Multi-region sampling within a lesion mitigated representation issues whilst distance-intensity relationships, as well as movement-instability issues, were demonstrated and ameliorated with post-processing techniques including normalisation and smoothing of extracted time-fluorescence curves. ML methods (automated feature extraction and classification) enabled ML algorithms glean excellent pathological categorisation results (AUC-ROC > 0.9, 37 rectal lesions) with imputation proving a robust method of compensation for interrupted time-series data with duration discrepancies. CONCLUSION: Purposeful clinical and data-processing protocols enable powerful pathological characterisation with existing clinical systems. Video analysis as shown can inform iterative and definitive clinical validation studies on how to close the translation gap between research applications and real-world, real-time clinical utility.

Real-time administration of indocyanine green in combination with computer vision and artificial intelligence for the identification and delineation of colorectal liver metastases.

Introduction: Fluorescence guided surgery for the identification of colorectal liver metastases (CRLM) can be better with low specificity and antecedent dosing impracticalities limiting indocyanine green (ICG) usefulness currently. We investigated the application of artificial intelligence methods (AIM) to demonstrate and characterise CLRMs based on dynamic signalling immediately following intraoperative ICG administration. Methods: Twenty-five patients with liver surface lesions (24 CRLM and 1 benign cyst) undergoing open/laparoscopic/robotic procedures were studied. ICG (0.05 mg/kg) was administered with near-infrared recording of fluorescence perfusion. User-selected region-of-interest (ROI) perfusion profiles were generated, milestones relating to ICG inflow/outflow extracted and used to train a machine learning (ML) classifier. 2D heatmaps were constructed in a subset using AIM to depict whole screen imaging based on dynamic tissue-ICG interaction. Fluorescence appearances were also assessed microscopically (using H&E and fresh-frozen preparations) to provide tissue-level explainability of such methods. Results: The ML algorithm correctly classified 97.2 % of CRLM ROIs (n = 132) and all benign lesion ROIs (n = 6) within 90-s of ICG administration following initial mathematical curve analysis identifying ICG inflow/outflow differentials between healthy liver and CRLMs. Time-fluorescence plots extracted for each pixel in 10 lesions enabled creation of 2D characterising heatmaps using flow parameters and through unsupervised ML. Microscopy confirmed statistically less CLRM fluorescence vs adjacent liver (mean ± std deviation signal/area 2.46 ± 9.56 vs 507.43 ± 160.82 respectively p < 0.001) with H&E diminishing ICG signal (n = 4). Conclusion: ML accurately identifies CRLMs from surrounding liver tissue enabling representative 2D mapping of such lesions from their fluorescence perfusion patterns using AIM. This may assist in reducing positive margin rates at metastatectomy and in identifying unexpected/occult malignancies.

The Atlantic divide: contrasting surgical robotics training in the USA, UK and Ireland.

The uptake of robotic surgery is rapidly increasing worldwide across surgical specialties. However, there is currently a much higher use of robotic surgery in the United States of America (USA) compared to the United Kingdom (UK) and Ireland. Reduced exposure to robotic surgery in training may lead to longer learning curves and worse patient outcomes. We aimed to identify whether any difference exists in exposure to robotic surgery during general surgical training between trainees in the USA, UK and Ireland. Over a 15-week period from September 2021, a survey was distributed through the professional networks of the research team. Participants were USA, UK or Irish trainees who were part of a formal general surgical training curriculum. 116 survey responses were received. US trainees (n = 34) had all had robotic simulator experience, compared to only 37.93% of UK (n = 58) and 75.00% of Irish (n = 24) trainees (p < 0.00001). 91.18% of US trainees had performed 15 or more cases as the console surgeon, compared to only 3.44% of UK and 16.67% of Irish trainees (p < 0.00001). Fifty UK trainees (86.21%) and 22 Irish trainees (91.67%) compared to 12 US trainees (35.29%) do not think they have had adequate robotics training (p < 0.00001). Surgical trainees in the USA have had significantly more exposure to training in robotic surgery than their UK and Irish counterparts.

Open versus laparoscopic liver resection of colorectal metastases: a meta-analysis of matched patient populations.

In recent years, the management of colorectal liver metastases (CRLM) has evolved significantly. Laparoscopic liver resection is increasingly being performed, despite a lack of major randomized controlled trial evidence or widespread international consensus. The objective of this review was to compare the short- and long-term outcomes following open and laparoscopic CRLM resection. A systematic review of comparative matched population studies was performed. Evaluated endpoints included surgical outcomes and survival outcomes. Twelve studies were included in this review, reporting on 3095 patients. R0 (negative margins) rates were higher in the laparoscopic CRLM group (89.3% versus 86.9%). In addition, laparoscopic resection was associated with less blood loss (486 mls versus 648 mls, p ≤ 0.0001*) and reduced blood transfusion rates (6.7% vs. 12.2%, OR 2.13, 95% CI 1.08-4.19, p = 0.03*). Major complication rates were higher in the open CRLM group (12.5% vs. 8.1%, OR 1.74, 95% CI 1.30-2.33, p = 0.03*), as was overall hospital length of stay (median 7 versus 5.5 days, p = 0.001*). Perioperative mortality was similar between both groups, and there was no significance in 5-year overall survival for open or laparoscopic CRLM resection groups (58% and 61% respectively). Laparoscopic CRLM resection is associated with less blood loss, lower transfusion rates, major complications, and overall hospital length of stay with comparable oncological outcome.

The impact of ursodeoxycholic acid on gallstone disease after bariatric surgery: a meta-analysis of randomized control trials.

BACKGROUND: Ursodeoxycholic acid (UDCA) is a bile acid that has been shown to reduce the formation of gallstones after significant weight loss. OBJECTIVE: This study aimed to evaluate the impact of UDCA on the incidence of gallstones after bariatric surgery. SETTINGS: An electronic search of PubMed (Medline), Cochrane Central Register of Controlled Studies (CENTRAL), Scopus (Elsevier) databases, EMBASE, CINAHL, Clinicaltrials.gov, and Web of Science. METHODS: A meta-analysis of randomized control trials was performed. The primary outcome was the incidence of gallstones after bariatric surgery. Secondary outcomes included type of operation and time interval to and characteristics associated with gallstone formation. RESULTS: Ten randomized control trials including 2583 patients were included, 1772 patients (68.6%) receiving UDCA and 811 (31.4%) receiving placebo. There was a significant reduction in gallstone formation in patients who received UDCA postoperatively (risk ratio [RR] .36, 95% confidence interval [CI] .22-.41, P < .00001). The overall prevalence of gallstone formation was 24.7% in the control group compared to 7.3% in the UDCA group. A dose of ≤600 mg/day had a significantly reduced risk of gallstone formation compared to the placebo group (risk ratio .35; 95% CI .24-.53; P < .001). The risk reduction was not significant for the higher dose (>600 mg/day) group (risk ratio .30; 95% CI, .09-1.01, P = .05). CONCLUSIONS: UDCA significantly reduces the risk of both asymptomatic and symptomatic gallstones after bariatric surgery. A dose of 600 mg/day is associated with improved compliance and better outcomes regardless of type of surgery. UDCA should be considered part of a standard postoperative care bundle after bariatric surgery.

Paraganglioma in an adolescent awaiting a cardiac transplant due to unrepaired congenital cyanotic heart disease and a univentricular heart: the first reported case.

We report a case of a 16-year-old adolescent male born with univentricular congenital cyanotic heart disease (CCHD) who was diagnosed with an incidental paraganglioma while awaiting a cardiac transplant. The coexistence of paraganglioma and univentricular CCHD is very rare, with no previous cases described in the literature of a patient concurrently requiring a cardiac transplant. The complex physiology associated with a common atrium, common ventricle, aortopulmonary lung perfusion and a hypoplastic left lung rendered our patient extremely vulnerable to catecholamine-mediated effects of preload, contractility and afterload. The interactions and interdependence between these systems provided unique difficulties for perioperative management with serious implications for prospective cardiac transplant.

Near-fatal mucormycosis post-double lung transplant presenting as uncontrolled upper gastrointestinal haemorrhage.

Invasive fungal infections in immunosuppressed transplant patients are associated with significant morbidity and mortality. We present a case of splenic mucormycosis post-double lung transplant, presenting as uncontrolled near-fatal upper gastrointestinal haemorrhage, to remind clinicians of the need to consider pre-transplant invasive fungal infection risk factors if an unexpected fungal infection arises in the post-transplant period. This case also highlights the valuable contribution of molecular technology for fungal identification but also the need for clinical correlation.

Mechanism of hard-nanomaterial clearance by the liver.

The liver and spleen are major biological barriers to translating nanomedicines because they sequester the majority of administered nanomaterials and prevent delivery to diseased tissue. Here we examined the blood clearance mechanism of administered hard nanomaterials in relation to blood flow dynamics, organ microarchitecture and cellular phenotype. We found that nanomaterial velocity reduces 1,000-fold as they enter and traverse the liver, leading to 7.5 times more nanomaterial interaction with hepatic cells relative to peripheral cells. In the liver, Kupffer cells (84.8 ± 6.4%), hepatic B cells (81.5 ± 9.3%) and liver sinusoidal endothelial cells (64.6 ± 13.7%) interacted with administered PEGylated quantum dots, but splenic macrophages took up less material (25.4 ± 10.1%) due to differences in phenotype. The uptake patterns were similar for two other nanomaterial types and five different surface chemistries. Potential new strategies to overcome off-target nanomaterial accumulation may involve manipulating intra-organ flow dynamics and modulating the cellular phenotype to alter hepatic cell interactions.

Docemur Docemus: Peer-Assisted Learning Improves the Knowledge Gain of Tutors in the Highest Quartile of Achievement but Not Those in the Lowest Quartile.

OBJECTIVES: Peer-assisted learning (PAL) is a form of collaborative learning where members of a peer group act as teachers for each other. A reciprocal PAL program was designed to investigate whether there were differential gains in knowledge acquisition among tutors compared with tutees. DESIGN: Bayesian statistical analysis was used to quantitatively assess the effect of tutor status on performance in a knowledge-based examination. Subgroup analysis according to student achievement and question difficulty was performed. PARTICIPANTS AND SETTING: Final year undergraduate medical students in a 5-year degree program (n = 126). RESULTS: The overall probability of getting a correct answer on the knowledge examination was 49.7%. For questions on topics where a student had acted as a tutor this improved to 57.3%. However, students who performed in the upper quartile had a greater percentage gain in the probability of a correct answer in topics that they had taught vs students who performed in the lowest quartile. CONCLUSIONS: There was demonstrable overall knowledge gain associated with acting as a tutor in a PAL program but the greatest gain occurred in students of highest academic ability.

Laparoscopic versus open liver resection for hepatocellular carcinoma at a North-American Centre: a 2-to-1 matched pair analysis.

INTRODUCTION: Oncological implications of laparoscopic resection in primary hepatic malignancy are not well defined. Laparoscopic liver resection (LLR) for hepatocellular carcinoma (HCC) in comparison to an open liver resection (OLR) in peri-operative and long-term oncological outcomes are described from a single North American institution. METHODS: From 2006 to 2013, all forty-three LLR patients for HCC were evaluated. Each patient was matched to two OLR patients for age at operation, maximal tumour size and tumour number. RESULTS: When compared with OLR, LLR had a lower severity of complication (0% versus 27%, P = 0.050) and lower 30-day readmission rate (2.3% versus 18.6%, P = 0.010). The length of stay (LOS) was shorter in LLR patients (5 versus 7 days, P < 0.001) and the estimated blood loss was also lower in LLR (300 versus 700 ml, P = 0.004). Admission to intensive care unit (ICU), emergency room (ER) visits and complication rates were similar. Overall, recurrence-free and intra-hepatic recurrence-free survival were comparable between LLR and OLR. DISCUSSION: LLR confers the widely-accepted benefits of laparoscopic surgery, namely severity of complication, 30-day readmission rate, LOS and blood loss. Further studies are required to examine intra- and extra-hepatic recurrence after LLR. LLR for HCC should be considered for appropriately selected patients in centres with requisite volume and expertise.

Mast cells in tissue healing: from skin to the gastrointestinal tract.

Mast cells are largely found at interfaces between the environment and the internal milieu. Early knowledge of the mast cell suggested a role predominantly associated with allergy and pathologic response to antigens, but more recent research has shown a myriad of functions is likely. Wound healing is a complex process of lysis and reconstitution controlled by a series of cell signalling proteins. Mast cells have been shown to play a significant role in the early inflammatory stage of wound healing and also influence proliferation and tissue remodelling in skin. Emerging work implicates the mast cell as a modulator of intestinal healing particularly following surgical anastomosis. The study of mast cells and wound healing involves the use of cell studies and animal models through the use of mast cell inhibitors, promoters and mast cell deficient rodent strains. This review addresses wound healing in skin and the gastrointestinal tract and specifically identifies data pertaining to the role of the mast cell in the process of cell breakdown, repair and regeneration.

Primary splenic lymphoma presenting with ascites.

An 84 year-old gentleman presented with abdominal distension, anorexia and occasional epigastric pain over a four-week period. Blood parameters revealed a hypochromic microcytic anaemia. Both CT and US scan identified ascites and a mass in the left upper quadrant. An ascitic tap was performed identifying bloody ascites and the presence of reactive mesothelial cells on cytology. A subsequent laparotomy and splenectomy was performed. Histology of the resected spleen revealed a Grade 2 follicular lymphoma (Figure 2). The patient had an uneventful postoperative recovery and was well at 6 months follow up. The spleen is an organ with an important immunological function. Primary splenic involvement occurs in less than 1% of non-hodgkin's lymphoma. Symptoms of primary splenic lymphoma (PSL) include pyrexia, weight-loss, night sweats, generalised weakness and left upper quadrant pain secondary to spleno - megaly. Ascites is a rare presenting feature of PSL. This report illustrates a case of primary splenic lymphoma which poses diagnostic challenges for the pathologist and clinician and ultimately requires definitive splenectomy to confirm a diagnosis.Figure 2Photograph of histology slide displaying the lymphoma at 10× magnification.

Electrical field stimulation promotes anastomotic healing in poorly perfused rat colon.

INTRODUCTION: Hypoperfusion of the bowel is a risk factor for anastomotic failure. Electrical field stimulation has been shown to improve repair in ischemic tissue, but its influence in hypoperfused colon has not been investigated. The hypothesis of this experimental animal study was that electrical field stimulation improves anastomotic healing in ischemic bowel. MATERIALS AND METHODS: Thirty rats were divided evenly into three groups: control, ischemia/placebo, and ischemia/test group. Ischemia was induced by ligation of the arterial supply to the proximal colon. The watershed area was identified and transected. Field stimulation was achieved by application of negatively charged diethylaminoethyl Sephadex beads in methylcellulose gel to the colonic epithelium prior to anastomosis. The placebo group had methylcellulose gel only applied and control animals had anastomosis only. Anastomotic strength was measured using anastomotic bursting pressure and hydroxyproline content. Systemic effect was investigated via interleukin-6 and vascular endothelial growth factor assay. RESULTS: The ischemia/electrical field stimulation (EFS) group had significantly increased bursting pressure and hydroxyproline content in comparison with the placebo group (P < 0.001). Serum cytokine levels were unaffected. CONCLUSION: Negatively charged EFS improves anastomotic healing in hypoperfused colon without induction of systemic cytokines and has potential as a local treatment in high-risk bowel anastomosis.