Learning curves in minimally invasive pancreatic surgery: a systematic review.

BACKGROUND: The learning curve of new surgical procedures has implications for the education, evaluation and subsequent adoption. There is currently no standardised surgical training for those willing to make their first attempts at minimally invasive pancreatic surgery. This study aims to ascertain the learning curve in minimally invasive pancreatic surgery. METHODS: A systematic search of PubMed, Embase and Web of Science was performed up to March 2021. Studies investigating the number of cases needed to achieve author-declared competency in minimally invasive pancreatic surgery were included. RESULTS: In total, 31 original studies fulfilled the inclusion criteria with 2682 patient outcomes being analysed. From these studies, the median learning curve for distal pancreatectomy was reported to have been achieved in 17 cases (10-30) and 23.5 cases (7-40) for laparoscopic and robotic approach respectively. The median learning curve for pancreaticoduodenectomy was reported to have been achieved at 30 cases (4-60) and 36.5 cases (20-80) for a laparoscopic and robotic approach respectively. Mean operative times and estimated blood loss improved in all four surgical procedural groups. Heterogeneity was demonstrated when factoring in the level of surgeon's experience and patient's demographic. CONCLUSIONS: There is currently no gold standard in the evaluation of a learning curve. As a result, derivations are difficult to utilise clinically. Existing literature can serve as a guide for current trainees. More work needs to be done to standardise learning curve assessment in a patient-centred manner.

Artificial liver support systems.

Artificial liver systems are used to bridge between transplantation or to allow a patient's liver to recover. They are used in patients with acute liver failure (ALF) and acute-on-chronic liver failure. There are five artificial systems currently in use: molecular adsorbent recirculating system (MARS), single-pass albumin dialysis (SPAD), Prometheus, selective plasma filtration therapy, and hemodiafiltration. The aim is to compare existing data on the efficiency of these devices. A literature search was conducted using online libraries. Inclusion criteria included randomized control trials or comparative human studies published after the year 2000. A systematic review was conducted for the five individual devices with a more detailed comparison of the biochemistry for the SPAD and MARS systems. Eighty-nine patients were involved in the review comparing SPAD and MARS. Results showed that there was an average reduction in bilirubin (-53 µmol/L in MARS and -50 µmol/L in SPAD), creatinine (-19.5 µmol/L in MARS and -7.5 µmol/L in SPAD), urea (-0.9 mmol/L in MARS and -0.75 mmol/L in SPAD), and gamma-glutamyl transferase (-0.215 µmol/L·s in MARS and -0.295 µmol/L·s in SPAD) in both SPAD and MARS. However, there was no significant difference between the changes in the two systems. This review demonstrated that both MARS and SPAD aid recovery of ALF. There is no difference between the efficiency of MARS and SPAD. Because of the limited data, there is a need for more randomized control trials. Evaluating cost and patient preference would aid in differentiating the systems.

Systematic review of the role of high intensity focused ultrasound (HIFU) in treating malignant lesions of the hepatobiliary system.

BACKGROUND: High Intensity Focused Ultrasound (HIFU) is an emerging non-invasive, targeted treatment of malignancy. The aim of this review was to assess the efficacy, safety and optimal technical parameters of HIFU to treat malignant lesions of the hepatobiliary system. METHODS: A systematic search of the English literature was performed until March 2020, interrogating Pubmed, Embase and Cochrane Library databases. The following key-words were input in various combinations: 'HIFU', 'High intensity focussed ultrasound', 'Hepatobiliary', 'Liver', 'Cancer' and 'Carcinoma'. Extracted content included: Application type, Exposure parameters, Patient demographics, and Treatment outcomes. RESULTS: Twenty-four articles reported on the clinical use of HIFU in 940 individuals to treat malignant liver lesions. Twenty-one studies detailed the use of HIFU to treat hepatocellular carcinoma only. Mean tumour size was 5.1 cm. Across all studies, HIFU resulted in complete tumour ablation in 55% of patients. Data on technical parameters and the procedural structure was very heterogeneous. Ten studies (n = 537 (57%) patients) described the use of HIFU alongside other modalities including TACE, RFA and PEI; 66% of which resulted in complete tumour ablation. Most common complications were skin burns (15%), local pain (5%) and fever (2%). CONCLUSION: HIFU has demonstrated benefit as a treatment modality for malignant lesions of the hepatobiliary system. Combining HIFU with other ablative therapies, particularly TACE, increases the efficacy without increasing complications. Future human clinical studies are required to determine the optimal treatment parameters, better define outcomes and explore the risks and benefits of combination therapies.

Novel non-invasive biomarkers diagnostic of acute rejection in renal transplant recipients: A systematic review.

BACKGROUND AND OBJECTIVES: Acute rejection is a significant complication detrimental to kidney transplant function. Current accepted means of diagnosis is percutaneous renal biopsy, a costly and invasive procedure. There is an urgent need to detect and validate non-invasive biomarkers capable of replacing the biopsy. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: Comprehensive literature searches of Medline, EMBASE and Cochrane Central Register of Controlled Trials databases were performed. Eligible studies were included as per inclusion criteria and assessed for quality using the GRADE quality of evidence tool. Outcomes evaluated included biomarker diagnostic performance, number of patients/samples, mean age and gender ratio, immunosuppression regime, in addition to clinical applications of the biomarker(s) tested. PRISMA guidelines were followed. Where possible, statistical analysis of comparative performance data was performed. RESULTS: 23 studies were included in this review, including 19 adult, 3 paediatric and 1 mixed studies. A total of 2858 participants and 50 candidate non-invasive tests were identified. Sensitivity, specificity and area under the curve performance values ranged 36%-100%, 30%-100% and 0.55-0.98, respectively. CONCLUSIONS: Although larger, more robust multi-centre validation studies are needed before non-invasive biomarkers can replace the biopsy, numerous candidate tests have demonstrated significant promise for various facets of postoperative management. Suggested uses include: ruling out patients with a low risk of acute rejection to avoid the need for biopsy, non-invasive testing where the biopsy is contraindicated and a prompt diagnosis is needed, and integration into a serial blood monitoring protocol in conjunction with serum creatinine.

Mitral valve repair or replacement in native valve endocarditis? Systematic review and meta-analysis.

OBJECTIVE: The objective of this study is to review the morbidity and mortality associated with mitral valve repair versus replacement in infective endocarditis patients. METHODS: A comprehensive search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all available data comparing mitral valve repair or replacement in infective endocarditis. Databases were evaluated and assessed to March 2017. Data were analyzed using meta-analytical techniques including odds ratio and mean weighted difference. RESULTS: A total of 8978 patients were analyzed in a total of 14 articles. The average age of the cohort was 53 years. Results revealed a shorter CPB time in the mitral valve (MV) repair compared to replacement group (P = 0.05). Postoperative outcomes (30 days/in hospital events) such as bleeding (P = 0.0047) and recurrence of infective endocarditis (IE) (P = 0.004) were significantly lower in the MV repair group. Beyond 30 days, recurrence of IE was higher in the MV replacement than the repair group (P < 0.0001). Additionally, there were significantly less reoperations in the repair group (P = 0.0021). The MV repair group had significantly better survival at 1 and 5 years postop (P < 0.0001, P < 0.0001). CONCLUSION: This meta-analysis shows that mitral valve repair has good clinical outcomes both in-hospital and at 1 and 5 years of follow-up. Mitral valve repair should be attempted in those patients in whom sufficient valve tissue is present for reconstruction after all infectious tissue has been resected.

Innominate artery cannulation in aortic surgery: A systematic review.

OBJECTIVE: The innominate artery is considered an alternative site for establishing cardiopulmonary bypass in surgical procedures involving the thoracic aorta. This systematic review examines the use of innominate artery cannulation in aortic surgery. METHODS: A systematic literature search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all studies that utilized innominate artery cannulation for establishing cardiopulmonary bypass and providing cerebral perfusion in thoracic aortic surgery. The data were reviewed up to September 2018. RESULTS: Acute type A aortic dissection contributed to 36% (n = 818) of the total 2,290 patients. 31.5% (n = 719) underwent surgery on the aortic root only; 54.5% (n = 1246) had ascending and hemi-arch replacement, while 11.5% had total aortic arch replacement and 2.5% had a frozen elephant trunk inserted. Postoperative stroke rate was 1.25% (n = 28), temporary neurological deficit was 4.8% (n = 111). All-cause 30-day mortality rate was 2.7% (n = 61). CONCLUSION: Innominate artery cannulation is a safe technique in patients who undergo thoracic aortic surgery. It can be utilized, in selected cases, as a reliable route for establishing cardiopulmonary bypass and maintaining cerebral perfusion.

Valve-Sparing Aortic Root Repair Compared to Composite Aortic Root Replacement: A Systematic Review and Meta-Analysis.

BACKGROUND: Aortic root aneurysms represent a significant risk of morbidity and mortality. Composite root replacement is the preferred practice for repair, although recently valve-sparing replacement has become a popular alternative. The study aim was to identify comparative studies that simultaneously analyzed composite root and valve-sparing root replacement outcomes. METHODS: A systematic review of the current literature was performed through four major databases, from inception until 2016. All comparative studies of valve-sparing versus composite root replacement were identified. All studies were assessed by two reviewers for their applicability and inclusion. RESULTS: A total of 12 comparative papers was identified encompassing 2,352 patients (700 valve-sparing and 1,652 composite); the mean follow up was 3.7 ± 1.7 years. Aortic cross-clamp and cardiopulmonary bypass times were lower in the composite group (p <0.0001 and p<0.00001, respectively). In-hospital mortality was low, but higher in the composite group (p = 0.002). Only one study reported long-term follow up. In studies reporting reoperation, there was slight difference favoring composite over valve-sparing replacement (p = 0.05). CONCLUSIONS: Valve-sparing and composite root replacement remain feasible options for replacement of the aortic root. Long-term data of comparative studies are not yet available to assess the viability of these procedures.

Comparing robotic, laparoscopic and open cystectomy: a systematic review and meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis comparing outcomes between Open Radical Cystectomy (ORC), Laparoscopic Radical Cystectomy (LRC) and Robot-assisted Radical Cystectomy (RARC). RARC is to be compared to LRC and ORC and LRC compared to ORC. MATERIAL AND METHODS: A systematic review of the literature was conducted, collating studies comparing RARC, LRC and ORC. Surgical and oncological outcome data were extracted and a meta-analysis was performed. RESULTS: Twenty-four studies were selected with total of 2,104 cases analyzed. RARC had a longer operative time (OPT) compared to LRC with no statistical difference between length of stay (LOS) and estimated blood loss (EBL). RARC had a significantly shorter LOS, reduced EBL, lower complication rate and longer OPT compared to ORC. There were no significant differences regarding lymph node yield (LNY) and positive surgical margins (PSM.) LRC had a reduced EBL, shorter LOS and increased OPT compared to ORC. There was no significant difference regarding LNY. CONCLUSION: RARC is comparable to LRC with better surgical results than ORC. LRC has better surgical outcomes than ORC. With the unique technological features of the robotic surgical system and increasing trend of intra-corporeal reconstruction it is likely that RARC will become the surgical option of choice.

Learning curves for urological procedures: a systematic review.

OBJECTIVE: To determine the number of cases a urological surgeon must complete to achieve proficiency for various urological procedures. PATIENT AND METHODS: The MEDLINE, EMBASE and PsycINFO databases were systematically searched for studies published up to December 2011. Studies pertaining to learning curves of urological procedures were included. Two reviewers independently identified potentially relevant articles. Procedure name, statistical analysis, procedure setting, number of participants, outcomes and learning curves were analysed. RESULTS: Forty-four studies described the learning curve for different urological procedures. The learning curve for open radical prostatectomy ranged from 250 to 1000 cases and for laparoscopic radical prostatectomy from 200 to 750 cases. The learning curve for robot-assisted laparoscopic prostatectomy (RALP) has been reported to be 40 procedures as a minimum number. Robot-assisted radical cystectomy has a documented learning curve of 16-30 cases, depending on which outcome variable is measured. Irrespective of previous laparoscopic experience, there is a significant reduction in operating time (P = 0.008), estimated blood loss (P = 0.008) and complication rates (P = 0.042) after 100 RALPs. CONCLUSIONS: The available literature can act as a guide to the learning curves of trainee urologists. Although the learning curve may vary among individual surgeons, a consensus should exist for the minimum number of cases to achieve proficiency. The complexities associated with defining procedural competence are vast. The majority of learning curve trials have focused on the latest surgical techniques and there is a paucity of data pertaining to basic urological procedures.

Evaluation of robotic and laparoscopic partial nephrectomy for small renal tumours (T1a).

OBJECTIVE: To compare laparoscopic partial nephrectomy (LPN) with robotic PN (RPN) using meta-analytical techniques, since there has been a rise in the incidence of small renal masses (SRM; <4 cm) minimally invasive approaches are becoming more popular in dealing with such pathologies. MATERIALS AND METHODS: A systematic review of the literature was performed to identify studies comparing LPN and RPN. Comparative studies evaluating RPN and LPN that fulfilled the inclusion criteria were selected. Data on preoperative, operative (operative time, estimated blood loss [EBL], and warm ischaemia time [WIT]), postoperative (length of stay [LOS]) variables and complications were collected. A meta-analysis using random effect model was performed. A further Bland-Altman analysis of some of the operative variables was done to compare their reproducibility and mean difference in techniques. RESULTS: Six studies matched the selection criteria. In all, 256 patients were analysed (40% RPN and 60% LPN). There was no significant different in EBL (P = 0.12, 95% confidence interval [CI] -12.01 to 104.26). Similarly, there was no significant different in WIT between the groups (P = 0.23, 95% CI -15.22 to 3.70). Also, LOS (P = 0.22, 95% CI -0.38 to 0.09) and overall postoperative complication rates were not significantly different between the groups (P = 0.84, 95% CI -0.05 to 0.06). CONCLUSIONS: Despite multiple studies reporting better perioperative variables for RPN, the present study found no significant differences between RPN and LPN. This has implications for both the surgeon and the patient. Lack of randomised controlled trials in addition to a lack of long-term oncological data for RPN are current limitations.

A comparison of mortality and indicators of treatment success of resuscitative endovascular balloon occlusion of aorta (REBOA): a systematic review and meta-analysis.

Background: Emergency resuscitative thoracotomy (RT) is a recognised method of controlling non-compressible torso haemorrhage (NCTH) often in adjunct to emergency surgery. Recently, there is much debate regarding resuscitative endovascular balloon occlusion of aorta (REBOA) on its role in civilian trauma cases in controlling NCTH. This study aims to provide an updated review on in-hospital mortality rates in patients who underwent REBOA versus RT and standard care without REBOA (non-REBOA) and to identify the potential indicators of REBOA survival. Methods: Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used to perform the study. All adult trauma cases were included, while pre-hospital, military and non-English studies were excluded. A literature search was done on studies from 01 January 2005 to 30 June 2020 using EMBASE, MEDLINE and COCHRANE databases. Risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool. Meta-analysis was conducted using a random effects model and the DerSimonian and Laird estimation method. A significance level of p < 0.05 was used. Results: Twenty-five studies were included in this study. The odds of in-hospital mortality of patients who underwent REBOA compared to RT was 0.18 (p < 0.01, 0.12-0.26). The odds of in-hospital survival of patients who underwent REBOA compared to non-REBOA was 1.28 (p = 0.62, 0.46-3.53). There was a significant difference found between survivors and non-survivors in terms of their pre-REBOA systolic blood pressure (SBP) (19.26 mmHg, p < 0.01), post-REBOA SBP (20.73 mmHg, p < 0.01), duration of aortic occlusion (- 40.57 min, p < 0.01) and injury severity score (- 8.50, p < 0.01). Conclusions: REBOA has a potential for wider application in civilian settings, with our study demonstrating lower in-hospital mortality compared to RT. Prospective multi-centre studies are needed for further evaluation of the indications and feasibility of REBOA.Level of Evidence + Study Type: Level IV. Systematic review with meta-analysis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-022-01413-3.

Role of circulating exosomal biomarkers and their diagnostic accuracy in pancreatic cancer.

Background and Aim: New biomarkers have the potential to facilitate early diagnosis of pancreatic cancer (PC). Circulating exosomes are cell-derived protein complexes containing RNA that can be used as indicators of cancer development. The aim of this review is to evaluate the current literature involving PC patient groups for highly accurate exosomal biomarkers. Methods: The literature search followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight-hundred and seventy-five studies were identified across various databases (Ovid MEDLINE, Embase, and Cochrane) published between 2009 and 2020. Nine studies fulfilled the inclusion criteria: human PC patients, diagnosis as outcome of interest, serum biomarker of exosomal content, reporting of diagnostic values, and disease progress. Area under the curve (AUC) of the exosomal biomarker was compared against that of CA19-9. Results: Nine papers were reviewed for relevant outcomes based on the inclusion criteria. These studies involved 565 participants (331 PC, 234 controls; male/female ratio 1.21; mean age 64.1). Tumor staging was reported in all studies, with 45.6% of PC patients diagnosed with early-stage PC (T1-2). The mRNA panel (ARG1, CD63, CK18, Erbb3, GAPDH, H3F3A, KRAS, ODC1) and GPC 1 reported the highest performing sensitivity and specificity at 100% each. The microRNA panel (miR-10b, miR-21, miR-30c, miR-181a, and miR-let7a), mRNA panel (ARG1, CD63, CK18, Erbb3, GAPDH, H3F3A, KRAS, ODC1), and GPC 1 showed a perfect AUC of 1.0. Five studies compared the AUC of the exosomal biomarker against CA19-9, each being superior to that of CA19-9. Conclusion: The potential of exosomal biomarkers remains promising in PC diagnosis. Standardization of future studies will allow for larger comparative analyses and overcoming contrasting findings.

Liver Ultrasound Histotripsy: Novel Analysis of the Histotripsy Site Cell Constituents with Implications for Histotripsy Application in Cell Transplantation and Cancer Therapy.

Introduction: Allogenic hepatocyte transplantation is an attractive alternative to whole-organ transplantation, particularly for the treatment of metabolic disorders and acute liver failure. However, the shortage of human donor organs for cell isolation, the low cell yield from decellularisation regimes, and low engraftment rates from portal administration of donor cells have restricted its clinical application. Using ultrasound histotripsy to provide a nidus in the liver for direct cell transplantation offers a new approach to overcoming key limitations in current cell therapy. We have analysed the liver cavity constituents to assess their potential as a site for cell delivery and implantation. Methods: Using human organ retrieval techniques, pig livers were collected from the abattoir and transported in ice-cold storage to the laboratory. Following 2 h of cold storage, the livers were flushed with organ preservation solution and placed on an organ perfusion circuit to maintain viability. Organs were perfused with Soltran™ organ preservation solution via the portal vein at a temperature of 24-30 °C. The perfusion circuit was oxygenated through equilibration with room air. Perfused livers (n=5) were subjected to ultrasound histotripsy, producing a total of 130 lesions. Lesions were generated by applying 50 pulses at 1 Hz pulse repetition frequency and 1% duty cycle using a single element 2 MHz bowl-shaped transducer (Sonic Concepts, H-148). Following histotripsy, a focal liver lesion was produced, which had a liquid centre. The fluid from each lesion was aspirated and cultured in medium (RPMI) at 37 °C in an incubator. Cell cultures were analysed at 1 and 7 days for cell viability and a live-dead assay was performed. The histotripsy sites were excised following aspiration and H&E staining was used to characterise the liver lesions. Cell morphology was determined by histology. Results: Histotripsy created a subcapsular lesion (~5 mm below the liver capsule; size ranging from 3 to 5 mm), which contained a suspension of cells. On average, 61×104 cells per mL were isolated. Hepatocytes were present in the aspirate, were viable at 24 h post isolation and remained viable in culture for up to 1 week, as determined by phalloidin/DAPI cell viability stains. Cultures up to 21 days revealed metabolically active live hepatocyte. Live-dead assays confirmed hepatocyte viability at 1 week (Day 1: 12% to Day 7: 45% live cells; p < 0.0001), which retained metabolic activity and morphology, confirmed on assay and microscopy. Cell Titre-GloTM showed a peak metabolic activity at 1 week (average luminescence 24.6 RLU; p < 0.0001) post-culture compared with the control (culture medium alone), reduced to 1/3 of peak level (7.85 RLU) by day 21. Conclusions: Histotripsy of the liver allows isolation and culture of hepatocytes with a high rate of viability after 1 week in culture. Reproducing these findings using human livers may lead to wide clinical applications in cell therapy.

Ultrasound Histotripsy on a Viable Perfused Whole Porcine Liver: Histological Aspects, Including 3D Reconstruction of the Histotripsy Site.

Non-invasive therapeutic-focused ultrasound (US) can be used for the mechanical dissociation of tissue and is described as histotripsy. We have performed US histotripsy in viable perfused ex vivo porcine livers as a step in the development of a novel approach to hepatocyte cell transplantation. The histotripsy nidus was created with a 2 MHz single-element focused US transducer, producing 50 pulses of 10 ms duration, with peak positive and negative pressure values of P+ = 77.7 MPa and P- = -13.7 MPaat focus, respectively, and a duty cycle of 1%. Here, we present the histological analysis, including 3D reconstruction of histotripsy sites. Five whole porcine livers were retrieved fresh from the abattoir using human transplant retrieval and cold static preservation techniques and were then perfused using an organ preservation circuit. Whilst under perfusion, histotripsy was performed to randomly selected sites on the live. Fifteen lesional sites were formalin-fixed and paraffin-embedded. Sections were stained with Haematoxylin and Eosin and picro-Sirius red, and they were also stained for reticulin. Additionally, two lesion sites were used for 3D reconstruction. The core of the typical lesion consisted of eosinophilic material associated with reticulin loss, collagen damage including loss of birefringence to fibrous septa, and perilesional portal tracts, including large portal vein branches, but intact peri-lesional hepatic plates. The 3D reconstruction of two histotripsy sites was successful and confirmed the feasibility of this approach to investigate the effects of histotripsy on tissue in detail.

New Insights on the Role of TRP Channels in Calcium Signalling and Immunomodulation: Review of Pathways and Implications for Clinical Practice.

Calcium is the most abundant mineral in the human body and is central to many physiological processes, including immune system activation and maintenance. Studies continue to reveal the intricacies of calcium signalling within the immune system. Perhaps the most well-understood mechanism of calcium influx into cells is store-operated calcium entry (SOCE), which occurs via calcium release-activated channels (CRACs). SOCE is central to the activation of immune system cells; however, more recent studies have demonstrated the crucial role of other calcium channels, including transient receptor potential (TRP) channels. In this review, we describe the expression and function of TRP channels within the immune system and outline associations with murine models of disease and human conditions. Therefore, highlighting the importance of TRP channels in disease and reviewing potential. The TRP channel family is significant, and its members have a continually growing number of cellular processes. Within the immune system, TRP channels are involved in a diverse range of functions including T and B cell receptor signalling and activation, antigen presentation by dendritic cells, neutrophil and macrophage bactericidal activity, and mast cell degranulation. Not surprisingly, these channels have been linked to many pathological conditions such as inflammatory bowel disease, chronic fatigue syndrome and myalgic encephalomyelitis, atherosclerosis, hypertension and atopy.

Warm versus cold cardioplegia in cardiac surgery: A meta-analysis with trial sequential analysis.

Objective: This meta-analysis aimed to compare clinical outcomes of warm and cold cardioplegia in cardiac surgeries in adult patients, with trial sequential analysis (TSA) used to determine the conclusiveness of the results. Methods: Electronic searches were performed on PubMed, Medline, Scopus, EMBASE, and Cochrane library to identify all studies that compared warm and cold cardioplegia in cardiac surgeries. Primary end points were in-hospital or 30-day mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, and new atrial fibrillation. Secondary end points were acute kidney injury, hospital length of stay, and intensive care unit length of stay. Prespecified subgroup analyses were performed for (1) studies published since publication of Fan and colleagues in 2010, (2) randomized controlled studies, (3) studies with low risk of bias, (4) coronary artery bypass graft surgeries, and (5) studies with cold blood versus those with cold crystalloid cardioplegia. TSA was performed to determine conclusiveness of the results, using on all outcomes without significant heterogeneity from studies of low risk of bias. Results: No significant differences were found between post-operative rates of mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, new atrial fibrillation, and acute kidney injury between warm and cold cardioplegia. TSA concluded that current evidence was sufficient to rule out a 20% relative risk reduction in these outcomes. Conclusions: Concerning safety outcomes, current evidence suggests that the choice between warm and cold cardioplegia remains in the surgeon's preference.

A systematic review and meta-analysis of mechanical vs biological composite aortic root replacement, early and 1-year results.

OBJECTIVE: Composite aortic root replacement is a standard procedure for various aortic root pathologies. This systematic review was set to identify the postoperative outcomes for composite mechanical root replacement (mCRR) compared to composite biological root replacement (bCRR). METHODS: We systematically reviewed four major databases for all papers assessing outcomes in composite root replacement. Articles selected were chosen by two reviewers. Amongst our inclusion and exclusion criteria, all pediatric populations were excluded as were studies with a cohort less than 50 patients. RESULTS: We identified seven studies that conformed to our inclusion criteria and incorporated 2240 patients. In-hospital mortality was higher but non-significant in the mechanical group (6.1 vs 4.2% respectively). There was no significant difference demonstrated in the risk of in-hospital stroke, late stroke and re-operation in either groups. Additionally, there was no significant difference in: endocarditis, 1-year mortality, 5-year mortality, mean cardiopulmonary or aortic cross-clamp time. CONCLUSIONS: Composite mechanical root offers no superiority to composite biological root. There is a significant increase in the perioperative bleeding amongst composite mechanical root cohort. There is a need for further randomized control trail to assess the efficacy of either methods.

Innominate vs. Axillary Artery Cannulation in Aortic Surgery: a Systematic Review and Meta-Analysis.

OBJECTIVE: To investigate whether axillary artery cannulation has supremacy over innominate artery cannulation in thoracic aortic surgery. METHODS: A comprehensive search was undertaken among the four major databases (PubMed, Excerpta Medica dataBASE [EMBASE], Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing axillary to innominate artery cannulation in thoracic aortic surgery. Databases were evaluated and assessed up to March 2017. RESULTS: Only three studies fulfilled the criteria for this meta-analysis, including 534 patients. Cardiopulmonary bypass time was significantly shorter in the innominate group (P=0.004). However, the innominate group had significantly higher risk of prolonged intubation > 48 hours (P=0.04) than the axillary group. Further analysis revealed no significant difference between the innominate and axillary groups for deep hypothermic circulatory arrest time (P=0.06). The relative risks for temporary and permanent neurological deficits as well as in-hospital mortality were not significantly different for both groups (P=0.90, P=0.49, and P=0.55, respectively). Length of hospital stay was similar for both groups. CONCLUSION: There is no superiority of axillary over innominate artery cannulation in thoracic aortic surgery in terms of perioperative outcomes; however, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing optimal arterial cannulation site.

Effect of tranexamic acid use on blood loss and thromboembolic risk in hip fracture surgery: systematic review and meta-analysis.

INTRODUCTION: Intravenous tranexamic acid (IV TXA) is a recognised pharmaceutical intervention utilised to minimise blood loss and allogenic blood transfusion. However, the use of IV TXA in hip fracture surgery remains inconclusive. We conducted a meta-analysis to investigate the role of TXA in operative hip fracture management on operative and total blood loss, allogenic blood transfusion requirements and impact on venous thromboembolic (VTE) event incidence. METHODS: A systematic computerised literature search of PubMed, Medline, Embase, Ovid, The Cochrane Controlled Trials Register, Trip and Google was conducted. We reviewed the efficacy of IV TXA on perioperative blood loss, total blood loss, pre- and postoperative haemoglobin differences, duration of surgery, allogenic blood transfusion requirements and VTE events. RESULTS: 8 studies were eligible including 6 randomised control trials and 2 cohort studies. Patients receiving IV TXA had reduced mean total blood loss of 442.9 mls (95% CI, 426.5-459.3; p<0.00001), reduced operative blood loss of 88.5 mls (95% CI, 59.9-117.2; p<0.00001), a decrease in the need for allogenic blood transfusion (OR 0.37; 95% CI, 0.26-0.53; p<0.00001) and a reduction in pre- and postoperative haemoglobin difference (p = 0.013.) There was no significant increase in VTE risk (OR 1.59; 95% CI 0.67-3.75; p>0.29) or significant difference on duration of surgery seen with IV TXA usage (p>0.06). CONCLUSIONS: Our review demonstrated the efficacy of IV TXA in minimising perioperative, reducing total blood loss and lowering the necessity for allogenic blood transfusions with no significant increased risk in VTE events.

Stented Versus Stentless Aortic Valve Replacement in Patients With Small Aortic Root: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of the study was to compare hemodynamic and perioperative outcomes of stented against stentless aortic valve replacement in patients with small aortic root (21 mm or less). METHODS: A comprehensive search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing stentless to stented bioprosthetic valves in small aortic root patients. Odds ratios, weighted mean differences, or standardized mean differences and their 95% confidence intervals were analyzed. RESULTS: A total of seven studies with a total of 965 patients fulfilled the inclusion criteria. There was no significant difference in preoperative baselines including mean age between both groups (P = 0.08), peak aortic valve gradient (P = 0.06), and effective orifice area (P = 0.28), whereas higher mean aortic valve gradient in the stented group (P = 0.007). No difference in cardiopulmonary bypass time (P = 0.74), aortic cross-clamp times (P = 0.88), intensive care unit stay (P = 0.13), and stroke rate (P = 0.56) were noted. However, stented group of patients showed higher rate of patient prosthesis mismatch (P = 0.0001) and longer total hospital stay (P = 0.002). Postoperatively, stentless group showed lower peak and mean aortic valve gradient (P = 0.003 and P = 0.008, respectively) with a better effective orifice area (P < 0.00001) at 6 months of follow-up. Mortality rates while in-hospital and at 1 year were similar in both groups (P = 0.94 and P = 0.86, respectively). CONCLUSIONS: Stentless aortic valves offer superior short-term hemodynamic outcomes in patients with small aortic root when compared with stented aortic valves. Although both groups have similar perioperative complications rates, stentless valves bring about a shorter hospital stay. A further large multicenter randomized controlled trial should address the longer-term benefit of stentless aortic valve over stented valve.