Impact of pre-existing mesh at the hiatus at revisional hiatal hernia surgery.

Recurrence after laparoscopic hiatus hernia repair (LHR) is high, with few symptomatic patients undergoing redo LHR. Morbidity is higher in redo surgery compared with the primary operation. Tens of studies have explored the safety of redoing LHR. However, the impact of existing mesh on operative risk is rarely examined. We aim to assess the impact of mesh at the hiatus on the safety of redo LHR. This was a cohort study examining redo LHR patients from a prospectively maintained database from January 2002 to December 2023. The primary outcome was intra-/postoperative complications. Follow-up was extracted from clinical records. Predictors of complications were assessed using univariable and multivariable logistic regression analyses. Redo LHR was performed in 100 patients; 22 had previous mesh. One encountered mortality with 23 complications. Five patients had absorbable mesh, with the remainder nonabsorbable. Overall complications were significantly higher with mesh at nine (40.9%) compared to no mesh redo at 14 (17.9%), P = 0.023. There was no difference in rates of visceral injury with mesh at four (18.2%) and no mesh at six (7.7%), P = 0.22. The median follow-up was 7 months; there was no difference in reflux rates (P = 0.70) but higher rates of dysphagia (P = 0.010). Higher overall complications were noted in patients with previous hiatal mesh repair at the time of LHR. However, major visceral complications were similar regardless of mesh use. Mesh at the hiatus should not be a deterrent for reoperative hiatus surgery.

Postoperative pancreatitis and pancreatic fistulae: a review of current evidence.

OBJECTIVES: Postoperative pancreatic fistula (POPF) represents one of the most severe complications following pancreatic surgery. Despite being a leading cause of morbidity and mortality, its pathophysiology is poorly understood. In recent years, there has been growing evidence to support the role of postoperative or post-pancreatectomy acute pancreatitis (PPAP) in the development of POPF. This article reviews the contemporary literature on POPF pathophysiology, risk factors, and prevention strategies. METHODS: A literature search was conducted using electronic databases, including Ovid Medline, EMBASE, and Cochrane Library, to retrieve relevant literature published between 2005 and 2023. A narrative review was planned from the outset. RESULTS: A total of 104 studies fulfilled criteria for inclusion. Forty-three studies reported on technical factors predisposing to POPF, including resection and reconstruction technique and adjuncts for anastomotic reinforcement. Thirty-four studies reported on POPF pathophysiology. There is compelling evidence to suggest that PPAP plays a critical role in the development of POPF. The acinar component of the remnant pancreas should be regarded as an intrinsic risk factor; meanwhile, operative stress, remnant hypoperfusion, and inflammation represent common mechanisms for acinar cell injury. CONCLUSIONS: The evidence base for PPAP and POPF is evolving. Future POPF prevention strategies should look beyond anastomotic reinforcement and target underlying mechanisms of PPAP development.

Clinical validation of the international study group of pancreatic surgery (ISGPS) definition for post-pancreatectomy acute pancreatitis.

BACKGROUND: The diagnosis of postoperative or post-pancreatectomy acute pancreatitis (PPAP) is controversial. In 2021, the International Study Group of Pancreatic Surgery (ISGPS) published the first unifying definition and grading system for PPAP. This study sought to validate recent consensus criteria, using a cohort of patients undergoing pancreaticoduodenectomy (PD) in a high-volume pancreaticobiliary specialty unit. METHODS: All consecutive patients undergoing PD at a tertiary referral centre between January 2016 and December 2021 were retrospectively reviewed. Patients with serum amylase recorded within 48h from surgery were included for analysis. Postoperative data were extracted and evaluated against the ISGPS criteria, including the presence of postoperative hyperamylasaemia, radiologic features consistent with acute pancreatitis, and clinical deterioration. RESULTS: A total of 82 patients were evaluated. The overall incidence of PPAP was 32% (26/82) in this cohort, of which 3/26 demonstrated postoperative hyperamylasaemia and 23/26 had clinically relevant PPAP (Grade B or C) when correlated radiologic and clinical criteria. CONCLUSIONS: This study is among the first to apply the recently published consensus criteria for PPAP diagnosis and grading to clinical data. While the results support their utility in establishing PPAP as a distinct post-pancreatectomy complication, there remains a need for future large-scale validation studies.

Unexpected deaths after endocrine surgery: learning from rare events using a national audit of surgical mortality.

BACKGROUND: The mortality rate is low in endocrine surgery, making it a difficult outcome to use for quality improvement in individual units. Lessons from population data sets are of value in improving outcomes. Data from the Australian and New Zealand Audit of Surgical Mortality (ANZASM) were used here to understand and elucidate potential systems issues that may contribute to preventable deaths. METHODS: ANZASM data relating to 30-day mortality after thyroidectomy, parathyroidectomy, and adrenalectomy from 2009 to 2020 were reviewed. Mortality rates were calculated using billing data. Thematic analysis of independent assessor reports was conducted to produce a coding framework. RESULTS: A total of 67 deaths were reported, with an estimated mortality rate of 0.03-0.07 per cent (38 for thyroidectomy (0.03-0.06 per cent), 16 for parathyroidectomy (0.03-0.06 per cent), 13 for adrenalectomy (0.15-0.33 per cent)). Twenty-seven deaths (40 per cent) were precipitated by clinically significant adverse events, and 18 (27 per cent) were judged to be preventable by independent ANZASM assessors. Recurrent themes included inadequate preoperative assessment, lack of anticipation of intraoperative pitfalls, and failure to recognize and effectively address postoperative complications. Several novel themes were reiterated, such as occult ischaemic heart disease associated with death after parathyroid surgery, unexpected intraoperative difficulties from adrenal metastasis, and complications due to anticoagulation therapy after thyroid surgery. CONCLUSION: This study represents a large-scale national report of deaths after endocrine surgery and provides insights into these rare events. Although the overall mortality rate is low, 27 per cent of deaths involved systems issues that were preventable following independent peer review.

The COVID-19 pandemic and access to health care in people with chronic kidney disease: A systematic review and meta-analysis.

AIM: This systematic review aims to evaluate the effect of the COVID-19 pandemic on access to health care for patients with CKD. METHODS: MEDLINE and EMBASE databases were searched up to July 2021 (PROSPERO CRD42021230831). Data relevant to access to health care before and during the COVID-19 pandemic were extracted, including outcomes related to access to general nephrology consultations, telehealth, dialysis services and kidney transplantations. Relative and absolute effects were pooled using a random effects model to account for between-study heterogeneity. Risk of bias was assessed using a modified Quality in Prognostic Studies tool. The certainty of the evidence was rated using the GRADE approach. RESULTS: Twenty-three studies across five WHO regions were identified. Reductions in transplantation surgeries were observed during the COVID-19 pandemic compared with the pre-COVID-19 era (risk ratio = 2.15, 95%CI = 1.51-3.06, I2  = 90%, p < .001). Additionally, six studies reported increased use of telehealth services compared with pre-COVID-19 times. Four studies found reduced access to in-person general nephrology services and six studies reported interruptions to dialysis services during the COVID-19 pandemic. CONCLUSION: Our findings suggest COVID-19 pandemic may have led to reductions in access to kidney transplantation, dialysis and in-person nephrology care. Meanwhile, whilst the use of telehealth has emerged as a promising alternate mode of health care delivery, its utility during the pandemic warrants further investigation. This study has highlighted major barriers to accessing care in a highly vulnerable chronic disease group.

Incidence and Outcomes of COVID-19 in People With CKD: A Systematic Review and Meta-analysis.

RATIONALE & OBJECTIVE: Coronavirus disease 2019 (COVID-19) disproportionately affects people with chronic diseases such as chronic kidney disease (CKD). We assessed the incidence and outcomes of COVID-19 in people with CKD. STUDY DESIGN: Systematic review and meta-analysis by searching MEDLINE, EMBASE, and PubMed through February 2021. SETTING & STUDY POPULATIONS: People with CKD with or without COVID-19. SELECTION CRITERIA FOR STUDIES: Cohort and case-control studies. DATA EXTRACTION: Incidences of COVID-19, death, respiratory failure, dyspnea, recovery, intensive care admission, hospital admission, need for supplemental oxygen, hospital discharge, sepsis, short-term dialysis, acute kidney injury, and fatigue. ANALYTICAL APPROACH: Random-effects meta-analysis and evidence certainty adjudicated using an adapted version of GRADE (Grading of Recommendations Assessment, Development and Evaluation). RESULTS: 348 studies (382,407 participants with COVID-19 and CKD; 1,139,979 total participants with CKD) were included. Based on low-certainty evidence, the incidence of COVID-19 was higher in people with CKD treated with dialysis (105 per 10,000 person-weeks; 95% CI, 91-120; 95% prediction interval [PrI], 25-235; 59 studies; 468,233 participants) than in those with CKD not requiring kidney replacement therapy (16 per 10,000 person-weeks; 95% CI, 4-33; 95% PrI, 0-92; 5 studies; 70,683 participants) or in kidney or pancreas/kidney transplant recipients (23 per 10,000 person-weeks; 95% CI, 18-30; 95% PrI, 2-67; 29 studies; 120,281 participants). Based on low-certainty evidence, the incidence of death in people with CKD and COVID-19 was 32 per 1,000 person-weeks (95% CI, 30-35; 95% PrI, 4-81; 229 studies; 70,922 participants), which may be higher than in people with CKD without COVID-19 (incidence rate ratio, 10.26; 95% CI, 6.78-15.53; 95% PrI, 2.62-40.15; 4 studies; 18,347 participants). LIMITATIONS: Analyses were generally based on low-certainty evidence. Few studies reported outcomes in people with CKD without COVID-19 to calculate the excess risk attributable to COVID-19, and potential confounders were not adjusted for in most studies. CONCLUSIONS: The incidence of COVID-19 may be higher in people receiving maintenance dialysis than in those with CKD not requiring kidney replacement therapy or those who are kidney or pancreas/kidney transplant recipients. People with CKD and COVID-19 may have a higher incidence of death than people with CKD without COVID-19.

Contrasting roles for BMP-4 and ventromorphins (BMP agonists) in TGFß-induced lens EMT.

Transforming growth factor beta (TGFß) and bone morphogenetic protein (BMP) signaling play opposing roles in epithelial-mesenchymal transition (EMT) of lens epithelial cells, a cellular process integral to the pathogenesis of fibrotic cataract. We previously showed that BMP-7-induced Smad1/5 signaling blocks TGFß-induced Smad2/3-signaling and EMT in rat lens epithelial cell explants. To further explore the antagonistic role of BMPs on TGFß-signaling, we tested the capability of BMP-4 or newly described BMP agonists, ventromorphins, in blocking TGFß-induced lens EMT. Primary rat lens epithelial explants were treated with exogenous TGFß2 alone, or in combination with BMP-4 or ventromorphins. Treatment with TGFß2 induced lens epithelial cells to undergo EMT and transdifferentiate into myofibroblastic cells with upregulated α-SMA and nuclear translocation of Smad2/3 immunofluorescence. BMP-4 was able to suppress this EMT without blocking TGFß2-nuclear translocation of Smad2/3. In contrast, the BMP agonists, ventromorphins, were unable to block TGFß2-induced EMT, despite a transient and early ability to significantly reduce TGFß2-induced nuclear translocation of Smad2/3. This intriguing disparity highlights new complexities in the responsiveness of the lens to differing BMP-related signaling. Further research is required to better understand the antagonistic relationship between TGFß and BMPs in lens EMT leading to cataract.

Expression of genes and proteins of the pax-six-eya-dach network in the metamorphic sea urchin: Insights into development of the enigmatic echinoderm body plan and sensory structures.

BACKGROUND: Photoreception-associated genes of the Pax-Six-Eya-Dach network (PSEDN) are deployed for many roles in addition to photoreception development. In this first study of PSEDN genes during development of the pentameral body in sea urchins, we investigated their spatial expression in Heliocidaris erythrogramma. RESULTS: Expression of PSEDN genes in the hydrocoele of early (Dach, Eya, Six1/2) and/or late (Pax6, Six3/6) larvae, and the five hydrocoele lobes, the first morphological expression of pentamery, supports a role in body plan development. Pax6, Six1/2, and Six3/6 were localized to the primary and/or secondary podia and putative sensory/neuronal cells. Six1/2 and Six3/6 were expressed in the neuropil region in the terminal disc of the podia. Dach was localized to spines. Sequential up-regulation of gene expression as new podia and spines formed was evident. Rhabdomeric opsin and pax6 protein were localized to cells in the primary podia and spines. CONCLUSIONS: Our results support roles for PSEDN genes in development of the pentameral body plan, contributing to our understanding of how the most unusual body plan in the Bilateria may have evolved. Development of sensory cells within the Pax-Six expression field is consistent with the role of these genes in sensory cell development in diverse species. Developmental Dynamics 247:239-249, 2018. © 2017 Wiley Periodicals, Inc.

Is There a Role for Heli-FX Endoanchors in Treating Type 1B Common Iliac Artery Endoleaks?

OBJECTIVES: The management of type 1B endoleaks following endovascular aortic aneurysm repair (EVAR) can be challenging. The Heli-FX Endoanchor system effectively treats proximal type 1A endoleaks but has not been used for type 1B common iliac artery endoleaks. This study demonstrates that it is both safe and effective in being used in the common iliac artery (CIA) limb of an EVAR. METHODS: A retrospective review of patients identified through coding and medical records was performed to extract information on demographics, aneurysmal features, operative features, and postoperative outcomes. This was then collated and analysed thoroughly and compared to existing research. RESULTS: Four patients with six type 1B CIA endoleaks were treated with Heli-FX Endoanchors in the CIA limbs of EVAR grafts. There was 100% technical success rate with complete exclusion of the endoleaks at 6 months. With mean follow up of 714 days, there were no Endoanchor-specific complications. One patient required explantation of the aortic endograft due to contralateral limb fracture, where it was found that an Endoanchor had penetrated the common iliac vein, requiring primary closure. CONCLUSIONS: Heli-FX Endoanchors were effective within this cohort of patients, though key risks were identified. Adjacent anatomy to the CIA must be considered, which also have nearly half the arterial thickness compared to the aorta. Pre-operative planning is essential given the theoretical risk of placing Endoanchors.

An elusive prostate tumour: Metastatic microcystic cribriform carcinoma presenting with imaging-histologic discordance.

Microcystic adenocarcinoma is an uncommon histologic variant of prostate carcinoma. Despite its rarity, it has gained increasing recognition over the past decade for its diagnostic challenges and unclear prognostic significance. Herein, we describe a rare case of metastatic microcystic prostate adenocarcinoma, presenting with discordance between imaging and histologic findings. This report highlights the diagnostic and therapeutic challenges of this pathological entity and the importance of multidisciplinary collaboration in the management of intermediate-risk prostate cancer.

Lipase-to-Amylase Ratio for the Prediction of Clinically Relevant Postoperative Pancreatic Fistula following Pancreaticoduodenectomy.

AIM: Postoperative pancreatic fistula(POPF) represents a leading cause of morbidity and mortality following major pancreatic resections. This study aimed to evaluate the use of post-operative drain fluid lipase-to-amylase ratio(LAR) for the prediction of clinically relevant fistulae(CR-POPF). METHODS: Consecutive patients undergoing pancreaticoduodenectomy between 2017-2021 at a tertiary centre were retrospectively reviewed. Univariable and multivariable analyses were performed to identify predictors for CR-POPF(ISGPS Grades B/C). Receiver operator characteristic(ROC) curve analyses were conducted to evaluate the performance of LAR and determine optimum prediction thresholds. RESULTS: Among 130 patients, 28(21.5%) developed CR-POPF. Variables positively associated with CR-POPF included soft gland texture, acinar cell density, diagnosis other than PDAC or chronic pancreatitis, resection without neoadjuvant therapy, and postoperative drain fluid lipase, amylase, and LAR(all p < 0.05). Multivariable regression analysis identified LAR as an independent predictor of CR-POPF(p < 0.05). ROC curve analysis showed that LAR had moderate ability to predict CR-POPF on POD1(AUC = 0.64,95%CI = 0.54-0.74) and excellent ability on POD3(AUC = 0.85,95%CI = 0.78-0.92) and POD5(AUC = 0.86,95%CI = 0.79-0.92). Optimum thresholds were consistent over POD1-5 (ratio > 2.6) and associated with 92% sensitivity and 46-71% specificity. CONCLUSION: Postoperative drain fluid LAR represents a reliable predictor for the development of CR-POPF. With early prognostication, the postoperative care of patients deemed at risk of developing high-grade fistulas may be optimised.

Ex vivo repair and autotransplantation for a complex renal artery aneurysm.

Renal artery aneurysms (RAA) are rare, occurring with an incidence of <0.1%. Open repair remains the mainstay of treatment for anatomically complex aneurysms. Here, we present a case of a large hilar RAA managed with ex vivo reconstruction and heterotopic renal autotransplantation. In this case, the complex anatomy and location of the aneurysm precluded the use of an endovascular approach. In situ repair was deemed unfavorable because of the technical difficulty of the repair with the numerous arterial branches involved, risk of parenchymal injury from prolonged warm ischemic time, restricted surgical field and risk of aneurysm rupture. This case contributes to the literature on laparoscopic nephrectomy, ex vivo repair and autotransplantation as a safe and viable treatment strategy for patients with complex RAA.

Surgical management of high-grade pancreatic injuries: Insights from a high-volume pancreaticobiliary specialty unit.

BACKGROUND: The management of high-grade pancreatic trauma is controversial. AIM: To review our single-institution experience on the surgical management of blunt and penetrating pancreatic injuries. METHODS: A retrospective review of records was performed on all patients undergoing surgical intervention for high-grade pancreatic injuries [American Association for the Surgery of Trauma (AAST) Grade III or greater] at the Royal North Shore Hospital in Sydney between January 2001 and December 2022. Morbidity and mortality outcomes were reviewed, and major diagnostic and operative challenges were identified. RESULTS: Over a twenty-year period, 14 patients underwent pancreatic resection for high-grade injuries. Seven patients sustained AAST Grade III injuries and 7 were classified as Grades IV or V. Nine underwent distal pancreatectomy and 5 underwent pancreaticoduodenectomy (PD). Overall, there was a predominance of blunt aetiologies (11/14). Concomitant intra-abdominal injuries were observed in 11 patients and traumatic haemorrhage in 6 patients. Three patients developed clinically relevant pancreatic fistulas and there was one in-hospital mortality secondary to multi-organ failure. Among stable presentations, pancreatic ductal injuries were missed in two-thirds of cases (7/12) on initial computed tomography imaging and subsequently diagnosed on repeat imaging or endoscopic retrograde cholangiopancreatography. All patients who sustained complex pancreaticoduodenal trauma underwent PD without mortality. The management of pancreatic trauma is evolving. Our experience provides valuable and locally relevant insights into future management strategies. CONCLUSION: We advocate that high-grade pancreatic trauma should be managed in high-volume hepato-pancreato-biliary specialty surgical units. Pancreatic resections including PD may be indicated and safely performed with appropriate specialist surgical, gastroenterology, and interventional radiology support in tertiary centres.

Meckel's diverticulectomy: a multi-centre 19-year retrospective study.

BACKGROUND: Meckels diverticulum (MD) causes a number of acute surgical pathologies and can contain ectopic tissue with the surgical aim to resect all ectopic mucosa. This has traditionally implied a small bowel resection (BR); though contemporary literature has demonstrated Meckel's diverticulectomy to be safe. The aim of this study was to determine optimal resection strategy, and assess MD histopathological features and their relationship to outcomes. METHODS: A 19-year retrospective review of patient medical records across seven hospitals was conducted with demographic, clinical and pathological data collected. Analysis was conducted using a student's t-test for continuous variables and chi-squared test for categorical variables. Univariate regression was performed to identify risk factors. P < 0.05 was considered statistically significant. RESULTS: One hundred and sixty patients underwent resection of MD, 70 (44%) had Meckel's diverticulectomy and 90 (56%) had BR. No significant difference in length (P = 0.486), width (P = 0.238), or ratio (P = 0.188) of diverticulectomy compared to BR, with fewer complications in diverticulectomy. In all, 24 (15.3%) MD were perforated, of whom 5 had gastric mucosa, 2 had mixed ectopic mucosa and 1 carcinoid tissue. There were no cases of ectopic mucosa in the resection margin requiring re-operation, or causing base perforation. MD specimen with greater length: width ratio was a risk factor for perforation OR 1.437 P = 0.042 but not for malignancy P = 0.813 or ectopic tissue P = 0.185. CONCLUSION: Meckel's diverticulectomy is safe via laparoscopic or open approach compared with BR. Despite higher perforation rates in MD with greater length: width ratio, no malignancy or ectopic risk was identified, supporting diverticulectomy as a safe operative approach.

Phaeohyphomycosis in Kidney Transplant Recipients: Highlighting the Importance of Early Recognition and Surgical Debridement.

Fungal infections are a recognized complication of immunosuppression in solid organ transplant recipients. Phaeohyphomycoses are fungal infections caused by a diverse group of dematiaceous fungi. Methods: We share the learning points from 2 Australian cases of phaeohyphomycosis secondary to Phaeacreomonium species (spp). A literature review was performed using Medline, Embase, and Google Scholar to identify this condition among kidney transplant recipients. Results: With the 2 cases reported in this article, a total of 17 cases were identified in the literature. Phaeacremonium spp is ubiquitous in humid and temperate flora, including Australia. Minor trauma is likely the source of inoculation in most cases and diagnosis is often delayed. Presently, no guidelines for management exist given the rarity of this condition. Most known cases have been treated with surgical debulking combined with long-course antifungal therapy. Conclusion: This paper describes 2 Australian cases of phaeohyphomycosis in kidney transplant recipients. A high index of suspicion, especially in the immunosuppressed, is essential for timely diagnosis in kidney transplant recipients. There are several diagnostic and therapeutic challenges that remain with this condition.

Improving testicular examinations on paediatric patients in the emergency department: A quality improvement study to improve early diagnosis of testicular torsion.

Objective: Male paediatric patients presenting with abdominal and/or testicular pain are common in the emergency department. As a time-sensitive diagnosis, the importance of early recognition, referral, and definitive management is critical. Missed or delayed diagnoses and management of testicular torsion can result in significant long-term sequelae including impaired fertility and psychological burden. In this quality improvement study, we utilised educational posters aiming to improve awareness of testicular torsion as a differential for abdominal pain and therefore, improve the quality of testicular examinations performed in the emergency department. Methods: Observational pre- and post-intervention study was conducted at a tertiary hospital emergency department. A pre-interventional retrospective review of the electronic medical records was conducted. All male patients under 16-years-old presenting with "abdominal pain" or "testicular problem" were included. We assessed the rate of testicular examination and the quality of the examination based on four domains: Cremasteric reflex, lie, swelling, and hardness. Educational posters targeting both patients and clinicians were placed around the emergency department. Subsequent review of the electronic medical records post-intervention was performed assessing the same domains. Results: A total of 235 presentations were analysed with 124 in the pre-intervention group and 111 in the post-intervention group. Overall rate of documented testicular examinations increased by 14% (p=0.032). The quality of testicular examinations also improved from an average of 0.85 domains documented to 2.29 post-intervention (p<0.001). Subgroup analysis found doctors in training had a greater improvement in both rate and quality of documented testicular examination. Conclusion: Our study demonstrated the value of continuing education in promoting awareness of testicular torsion in the emergency department. We found a clear improvement in the quality of clinical documentation of a time-sensitive condition which may infer a decreased risk of missed and delayed diagnosis of testicular torsion.

The efficacy and cost-effectiveness of enoxaparin versus rivaroxaban in the prevention of venous thromboembolism following total hip or knee arthroplasty: A meta-analysis.

INTRODUCTION: Thromboprophylaxis following total hip and knee arthroplasty is variable across institutions, but commonly consists of enoxaparin, and more recently rivaroxaban. We aimed to analyze the current evidence on the efficacy, safety and cost-effectiveness of rivaroxaban versus enoxaparin for thromboprophylaxis following TKA or THA. METHODS: This study was conducted according to PRISMA guidelines. Electronic database searches were performed using three databases from their dates of inception to June 2020. Relevant randomized controlled studies were identified, with data extracted and analyzed. RESULTS: From eight studies, 13,384 patients were included, with 5700 undergoing TKA and 7684 undergoing THA. There were 6629 patients receiving rivaroxaban and 6755 patients receiving enoxaparin. From the total cohort, rivaroxaban was associated with significantly lower rates of major VTE (p = 0.009) and DVT (p < 0.001) when compared to enoxaparin. There was no significant difference in bleeding complications between rivaroxaban and enoxaparin groups (p = 0.14). Subgroup analysis of patients undergoing THA demonstrated that rivaroxaban reduced risk of major VTE (p = 0.002) and DVT (p = 0.01) with no significant differences in any other complications. For those undergoing TKA, rivaroxaban significantly reduced the risk of DVT (p < 0.001) but was associated with higher rates of post-operative blood transfusion (p = 0.03). Cost-analysis revealed that rivaroxaban was superior to enoxaparin, with the medication cost needed to prevent one DVT being $1081 and $432 less with rivaroxaban for THA and TKA respectively. CONCLUSIONS: Rivaroxaban may be a safe and cost-effective alternative to enoxaparin for routine thromboprophylaxis following total knee or hip arthroplasty.

Involvement of Kommerell's diverticulae-a new anatomical risk factor for acute aortic syndrome progression and technical considerations.

We present two cases of acute aortic syndromes (AAS), involving an aberrant right subclavian artery (ARSA) with associated Kommerell's diverticulae (KD). One of the cases involves a penetrating aortic ulcer in patients with an ARSA and KD and represents the first reported such case in the literature. Both cases progressed despite optimal medical therapy suggesting AAS with this anomalous anatomy needs a more aggressive operative approach. The involvement of KD in a patient with AAS appears to increase aortic disease progression and this anatomical variation should be considered another anatomical criterion that may place these patients at higher risk of complication. Progression during conservative management and waiting for the patient to be in the traditional safer 'sub-acute' time frame after presentation increased the eventual difficulty of the hybrid repair. A hybrid open-endovascular repair was utilized in all cases and is a safe and effective strategy for managing patients with ARSA and KD presenting with AAS.

Postoperative superior mesenteric artery syndrome following appendicectomy: A case report.

INTRODUCTION: Superior mesenteric artery syndrome is a rare cause of proximal intestinal obstruction. It is caused by a narrow aortomesenteric angle resulting in external compression of the duodenum as it traverses between the abdominal aorta and the superior mesenteric artery. Presenting symptoms tend to be non-specific and aetiological risk factors for this syndrome remain subjects to debate. The lack of awareness for this phenomenon often results in a delayed diagnosis, yet it can predispose to potentially life-threatening complications. CASE PRESENTATION: We describe an acquired case of SMA syndrome, in an 88-year old male who underwent an open appendicectomy 20 years prior. The patient presented with an 18-month history of progressive anorexia, weight loss, and intractable vomiting. After inconclusive initial investigations, an exploratory laparotomy demonstrated extensive postoperative adhesions, placing traction on the SMA through its ileocolic branch, resulting in acute angulation of the SMA and subsequent external duodenal compression. DISCUSSION: This case illustrates the acute evolving presentation of gastric and duodenal obstruction associated with SMA syndrome, and the need to raise the index of suspicion for its diagnosis. In this case, it is postulated that SMA syndrome presented as a late complication of an open appendicectomy - A rare presentation for a rare disease. CONCLUSION: SMA syndrome is an uncommon, but important differential for upper gastrointestinal obstruction. This case illustrates the challenges in the diagnosis of this rare clinical entity. Further study is warranted to understand the varied aetiology and optimal management for patients presenting with SMA syndrome.