Application of Novosorb biodegradable temporising matrix in wounds of different aetiologies: a case series.

DECLARATION OF INTEREST: The authors have no conflicts of interest to declare.

Systematic Review and Meta-analysis of Fenestrated and Chimney/Snorkel Techniques for Endovascular Repair of Juxtarenal Aortic Aneurysms.

OBJECTIVES: Comparative effectiveness of fenestrated endovascular aneurysm repair (FEVAR) and chimney graft endovascular aneurysm repair (ChEVAR) for juxtarenal aortic aneurysms (JAAs) remains unclear. Our objective was to identify and analyze the current body of evidence comparing the effectiveness of both techniques for JAA. METHODS: We performed a systematic review and meta-analysis comparing the effectiveness of FEVAR and ChEVAR for JAA repair. We searched MEDLINE, EMBASE, and Cochrane Register for Controlled Trials from January 1, 1990, for randomized and non-randomized studies assessing outcomes of FEVAR and ChEVAR for JAA repair. Screening, data extraction, risk of bias assessment, and GRADE (Grading of Recommendations, Assessments, Development, and Evaluations) certainty of evidence were performed in duplicate. Data were pooled statistically where possible. RESULTS: Nine retrospective cohort studies comparing the use of FEVAR and ChEVAR for juxtarenal aneurysm were included for meta-analysis. The FEVAR and ChEVAR arms of the meta-analysis consisted of 726 participants and 518 participants, respectively. There were 598 (86.8%) and 332 (81.6%) men in each arm. The mean diameter was larger in the ChEVAR arm (59 mm vs 52.5 mm). Both techniques had similar rates of postoperative 30-day mortality, 3.38% (8/237) versus 3.52% (8/227), acute kidney injury, 16.76% (31/185) versus 17.31% (18/104), and major adverse cardiac events, 7.30% (46/630) versus 6.60% (22/333). The meta-analysis supported the use of FEVAR for most outcomes, with significant advantage for technical success (odds ratio [OR]: 3.24, 95% CI: 1.24-8.42) and avoidance of type 1 endoleak (OR: 5.76, 95% CI: 1.94-17.08), but a disadvantage for spinal cord ischemia (OR: 10.21, 95% CI: 1.21-86.11), which had a very low number of events. The quality of evidence was "moderate" for most outcomes. CONCLUSION: Both endovascular techniques had good safety profiles. The evidence does not support superiority of either FEVAR or ChEVAR for JAA. CLINICAL IMPACT: While lack of equipoise has hampered the design of randomised trials of open versus endovascular repair of juxtarenal aortic aneurysms, concern about the durability of endovascular repair highlights the need for stronger evidence of the comparative efficacy of endovascular techniques. This review performed meta-analysis and evidence appraisal of recent data from large observational studies comparing fenestrated and chimney techniques, using a comprehensive outcome set. Superiority of either intervention could not be established due to differences in participants' baseline risk in each study arm. However, data suggests that both techniques are safe and suitable for use when indicated.

Long-term outcome of cervical artery dissection.

OBJECTIVE: The aim of the study is to evaluate the natural history of extracranial cervical artery dissection (CAD) including comorbidities, symptoms at presentation, recurrence of symptoms, and long-term outcome following different treatment approaches. METHODS: A retrospective review of patients treated for acute CAD was performed over a 5-year period from January 2017 to April 2022. RESULTS: Thirty-nine patients were included in the study, 25 (64.1%) with acute internal carotid artery dissection and 14 (35.9%) with acute vertebral artery dissection. Thirty-four patients (87.1%) had spontaneous CAD, and five patients (12.8%) had traumatic CAD. The mean age of the cohort was 54.2 years. The mean time from symptom onset to presentation was 4.34 days. The most common symptoms in internal carotid artery dissection were unilateral weakness (44%), headache (44%), slurred speech (36%), facial droop (28%), unilateral paraesthesia (24%), neck pain (12%), visual disturbance (8%), and Horner's syndrome (8%). The most common symptoms in vertebral artery dissection were headache (35.7%), neck pain (35.7%), vertigo (28.57%), ataxia (14.28%), and slurred speech (14.28%). The imaging modalities used for diagnosis included computed tomography angiography (48.7%), magnetic resonance angiography (41%), and duplex ultrasound (10.2%). In patients with carotid artery dissection, 57% had severe stenosis, 24% had moderate stenosis, and 20% had mild stenosis. All patients treated were managed conservatively with either anticoagulation or antiplatelets. Long-term clinical follow-up was available for 33 patients (84.6%). Thirty patients (90.9%) reported complete resolution of symptoms, and three patients (9%) reported persistent symptoms. Anatomic follow-up with imaging was available for 17 patients (43.58%). Thirteen patients (76.47%) had complete resolution of dissection, two patients (11.76%) had partial resolution of dissection, and two patients (11.76%) had persistent dissection. There was one death unrelated to CAD in a multi-trauma patient. There were four early recurrent symptoms in the first 3 to 8 weeks post discharge. The mean follow-up time was 308.27 days. CONCLUSIONS: The majority of CADs can be managed conservatively with good clinical and anatomical outcome and low rates of recurrence.

Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study.

OBJECTIVES: Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus. METHODS: A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). 'Good' and 'very good' consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively. RESULTS: Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, 'good' and 'very good' consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, 'very good' consensus was achieved for 3/3 statements. CONCLUSIONS: The main findings from this study were that there was 'good' or 'very good' consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.

Transient iatrogenic Horner's syndrome following carotid endarterectomy.

We present a case of a 72-year-old man who developed a transient Horner's syndrome in the immediate postoperative period after right carotid endarterectomy which resolved within 3 months. Although Horner's syndrome has been reported with several disorders of the carotid artery, our case documents a rare iatrogenic oculosympathetic paresis after elective carotid endarterectomy.

End-To-Side versus Side-To-Side Anastomosis in Upper Limb Arteriovenous Fistula for Dialysis Access: A Systematic Review and a Meta-Analysis.

BACKGROUND: An arteriovenous fistula (AVF) is the best modality for hemodialysis access. The end-to-side (ETS) technique has been suggested in the literature to produce superior results to the side-to-side (STS) approach; however, in the absence of a systematic review, this practice remains debatable. METHODS: Online search for randomized controlled trials and observational studies that compared the ETS versus the STS anastomosis techniques in creating an upper limb AVF. Aims were to systematically assess the difference between both procedures in terms of access maturation, patency, and postoperative complications. RESULTS: Seven studies were included with 463 patients in the ETS group and 523 in the STS group. The difference between the 2 techniques was not significant in relation to patency rates at 3, 6, 12, and 24 months (P values: 0.28, 0.82, 0.54, and 0.21, respectively). There were fewer cases of postoperative hematoma in the ETS group; however, the difference was not significant (P = 0.09). Arterial steal syndrome was found to be significantly associated with the STS configuration in pooled analysis (pooled risk ratio = 0.11 [0.01-0.88], 95% CI, P = 0.04). CONCLUSIONS: Similar maturation rates between ETS and STS fistula configuration, however, arterial steal syndrome was significantly associated with the STS technique. ETS will likely remain as the preferred AVF configuration as it is less technically demanding.

Development of a Non-Aqueous Dispersion to Improve Intestinal Epithelial Flux of Poorly Permeable Macromolecules.

Intestinal permeation enhancers (PEs) offer an attractive strategy to enable oral peptide administration. However, optimal presentation of peptide and PE from solid-dosage forms is offset by slow dissolution rates in the small intestine, which reduces the likelihood that the PE can reach the threshold concentration for sufficient permeability enhancement. The purpose of this study was to design a PE-based liquid dispersion that can improve intestinal permeation of macromolecules across Caco-2 monolayers and isolated rat/human intestinal mucosae mounted in Ussing chambers. An enhancer screen in monolayers based on permeability (TEER, Papp [14C]-mannitol) and cytotoxicity (MTT assay) initially identified methyl 10-hydroxydecanoate (10-OHC10CH3) as a candidate. 10-OHC10CH3 (20 mM) increased the Papp of fluorescent dextran of 4 kDa (FD4) (167-fold), 10 kDa (FD10) (429-fold), and 40 kDa (FD40) (520-fold) across monolayers. Blends of 10-OHC10CH3 with low molecular weight PEGs (0.2-1 kDa) formed liquid dispersions in which enhancement capacity across monolayers of 10-OHC10CH3 was increased over 10-OHC10CH3 alone in the order PEG200 < PEG400 < PEG600 < PEG1000. Finally, a 1:5 ratio of 10-OHC10CH3 (10-20 mM)/PEG600 (50-100 mM) increased the Papp of [14C]-mannitol across rat and human intestinal mucosae. This study highlights the potential future role for non-aqueous, PE-based liquid dispersions in oral delivery of macromolecules.

Preconditioning Shields Against Vascular Events in Surgery (SAVES), a multicentre feasibility trial of preconditioning against adverse events in major vascular surgery: study protocol for a randomised control trial.

BACKGROUND: Patients undergoing vascular surgery procedures constitute a 'high-risk' group. Fatal and disabling perioperative complications are common. Complications arise via multiple aetiological pathways. This mechanistic redundancy limits techniques to reduce complications that target individual mechanisms, for example, anti-platelet agents. Remote ischaemic preconditioning (RIPC) induces a protective phenotype in at-risk tissue, conferring protection against ischaemia-reperfusion injury regardless of the trigger. RIPC is induced by repeated periods of upper limb ischaemia-reperfusion produced using a blood pressure cuff. RIPC confers some protection against cardiac and renal injury during major vascular surgery in proof-of-concept trials. Similar trials suggest benefit during cardiac surgery. Several uncertainties remain in advance of a full-scale trial to evaluate clinical efficacy. We propose a feasibility trial to fully evaluate arm-induced RIPC's ability to confer protection in major vascular surgery, assess the incidence of a proposed composite primary efficacy endpoint and evaluate the intervention's acceptability to patients and staff. METHODS/DESIGN: Four hundred major vascular surgery patients in five Irish vascular centres will be randomised (stratified for centre and procedure) to undergo RIPC or not immediately before surgery. RIPC will be induced using a blood pressure cuff with four cycles of 5 minutes of ischaemia followed by 5 minutes of reperfusion immediately before the start of operations. There is no sham intervention. Participants will undergo serum troponin measurements pre-operatively and 1, 2, and 3 days post-operatively. Participants will undergo 12-lead electrocardiograms pre-operatively and on the second post-operative day. Predefined complications within one year of surgery will be recorded. Patient and staff experiences will be explored using qualitative techniques. The primary outcome measure is the proportion of patients who develop elevated serum troponin levels in the first 3 days post-operatively. Secondary outcome measures include length of hospital and critical care stay, unplanned critical care admissions, death, myocardial infarction, stroke, mesenteric ischaemia and need for renal replacement therapy (within 30 days of surgery). DISCUSSION: RIPC is novel intervention with the potential to significantly improve perioperative outcomes. This trial will provide the first evaluation of RIPC's ability to reduce adverse clinical events following major vascular surgery. TRIAL REGISTRATION: www.clinicaltrials.gov NCT02097186 Date Registered: 24 March 2014.

Zinc sulphate attenuates chloride secretion in human colonic mucosae in vitro.

Zinc's usefulness in the treatment of diarrhoea is well established as an addition to oral rehydration. Mechanisms of action of zinc have been explored in intestinal epithelia from rodents and in cell lines. The aim was to examine how zinc alters ion transport and signal transduction in human colon in vitro. Voltage clamped colonic sheets obtained at the time of surgical resection were used to quantify ion transport responses to established secretagogues. Nystatin permeabilisation was used to study basolaterally-sited ion channels. Direct actions of zinc were determined using preparations of colonic crypts isolated from human mucosal sheets. Electrophysiological measurements revealed zinc to be an inhibitor of electrogenic ion transport stimulated by forskolin, PGE(2), histamine and carbachol in isolated human colonic epithelium. Basolateral addition of zinc sulphate had no direct effect on the epithelium. To further outline the mechanism of action, levels of secondary intracellular messengers (3', 5'-cyclic adenosine monophosphate; cAMP) were determined in isolated colonic crypts, and were found to be reduced by zinc sulphate. Finally, indirect evidence from nystatin-permeabilised mucosae further suggested that zinc inhibits basolateral K(+) channels, which are critical for transepithelial Cl(-) secretion linked to water flux. Anti-secretory, and therefore anti-diarrhoeal, actions of exogenous zinc are due, at least in part, to direct basolateral epithelial K(+) channel inhibition.

Mechanisms of action of zinc on rat intestinal epithelial electrogenic ion secretion: insights into its antidiarrhoeal actions.

OBJECTIVES: Zinc is a useful addition to oral rehydration therapy for acute diarrhoea. We have assessed the mechanism of its epithelial antisecretory action when intestinal epithelial tight junctions were pharmacologically opened. METHODS: Rat isolated ileal and colonic mucosae were mounted in Ussing chambers and exposed to ZnSO(4) (Zn(2+) ) in the presence of secretagogues and inhibition of short circuit current (I(sc) ) was measured. KEY FINDINGS: Pre-incubation with basolateral but not apical Zn(2+) reduced I(sc) stimulated by forskolin, carbachol and A23187. In the presence of the tight junction-opener, cytochalasin D, antisecretory effects of apically-applied Zn(2+) were enabled in colon and ileum. The apparent permeability coefficient (P(app) ) of Zn(2+) was increased 1.4- and 2.4-fold across rat ileum and colon, respectively, by cytochalasin D. Basolateral addition of Zn(2+) also reduced the I(sc) stimulated by nystatin in rat colon, confirming K channel inhibition. In comparison with other inhibitors, Zn(2+) was a relatively weak blocker of basolateral K(ATP) and K (Ca2+) channels. Exposure of ileum and colon to Zn(2+) for 60 min had minimal effects on epithelial histology. CONCLUSIONS: Antisecretory effects of Zn(2+) on intestinal epithelia arose in part through nonselective blockade of basolateral K channels, which was enabled when tight junctions were open.

The flavonone naringenin inhibits chloride secretion in isolated colonic epithelia.

Studies investigating the activating and inhibitory actions of bioflavonoids on colonic function have yielded conflicting results. At low concentrations, flavonoids may stimulate chloride secretion while at higher concentrations they may have antisecretory actions in the colon. Naringenin (4',5,7-trihydroxyflavanone), found predominantly in citrus fruits, confers a protective effect against colorectal cancer and is purported to modulate secretory function in colonic cell lines. The aim of this study was to investigate the effects of naringenin on ion transport in rat and human colonic mucosae. Naringenin inhibited basal and stimulated chloride secretion in rat and human colonic mucosae mounted in Ussing chambers (IC(50) 330 µMol/L and 360 µMol/L respectively) and did not alter intracellular cAMP generation. Naringenin inhibited chloride secretion in MQAE (N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide) loaded crypts stimulated with forskolin. In BCECF (2',7'-bis-(2-carboxyethyl)-5-(and 6)-carboxyfluorescein acetoxymethyl ester) loaded crypts, naringenin caused an intracellular acidification (ΔpH/min=0.05 ± 0.004) which was sensitive to the Na-K-Cl co-transporter (NKCC) inhibitor bumetanide. In addition, the antisecretory effect of naringenin was not inhibited by blockade of barium sensitive basolateral K(+) transporters or by inhibition of Na+/H(+) exchange by amiloride. We propose that the antisecretory action of naringenin is due to inhibition of basolateral NKCC1 in rat and human colon.

Emerging role of hydrogen sulfide in colonic physiology and pathophysiology.

Hydrogen sulfide (H2S) is a toxic gas that is now recognized as an important mediator of many physiological processes. In the colon, H2S is produced both endogenously and by naturally occurring sulfate-reducing bacteria (SRB). The full arrays of its effects in the gastrointestinal tract are still being elucidated, but they range from motility to carcinogenesis. We examined the evidence relating to H2S as a modulator of colonic function and disease. H2S is implicated in modulation of colonic compliance through its action on smooth muscle. There is also evidence linking H2S to colonic nociception, inflammatory bowel disease (IBD), and colorectal cancer. The exact mechanisms and pathways by which H2S exerts its multitude of effects are not yet fully understood, but its involvement in physiological and pathophysiological conditions of the colon is becoming evident. Elucidating the intricate effects of H2S in the colon and understanding the exact nature of its interactions with the colon makes pharmacological modulation of H2S production and metabolism potential targets for treatment of a multitude of colonic conditions in the future.

Small bowel obstruction secondary to migration of a fragment of lithobezoar: a case report.

INTRODUCTION: Small bowel obstruction is a common world-wide condition that has a range of etiological factors. The management is largely dependent on the cause of the obstruction. Small bowel obstruction caused by foreign body ingestion is rare; many items have been reported as responsible, but there are no reports implicating polyurethane foam. CASE PRESENTATION: We report the case of a 44-year-old Irish male who presented following ingestion of polyurethane foam. He was asymptomatic on presentation but developed a small bowel obstruction shortly thereafter. CONCLUSION: Patients presenting following ingestion of polyurethane foam should be scheduled for elective laparotomy, gastrotomy, and retrieval of the cast on the next available theatre list - given that they are suitable for surgery.