Gastro-esophageal diagnostic workup before bariatric surgery or endoscopic treatment for obesity: position statement of the International Society of Diseases of the Esophagus

Obesity is a chronic and multifactorial condition characterized by abnormal weight gain due to excessive adipose tissue accumulation that represents a growing worldwide challenge for public health. In addition, obese patients have an increased risk of hiatal hernia, esophageal, and gastric dysfunction, as well as gastroesophageal reflux disease, which has a prevalence over 40% in those seeking endoscopic or surgical intervention. Surgery has been demonstrated to be the most effective treatment for severe obesity in terms of long-term weight loss, comorbidities, and quality of life improvements and overall mortality decrease. The recent emergence of bariatric endoscopic techniques promises less invasive, more cost-effective, and reproducible approaches to the treatment of obesity. With the endorsement of the International Society for Diseases of the Esophagus, we started a Delphi process to develop consensus statements on the most appropriate diagnostic workup to preoperatively assess gastroesophageal function before bariatric surgical or endoscopic interventions. The Consensus Working Group comprised 11 international experts from five countries. The group consisted of gastroenterologists and surgeons with a large expertise with regard to gastroesophageal reflux disease, bariatric surgery and endoscopy, and physiology. Ten statements were selected, on the basis of the agreement level and clinical relevance, which represent an evidence and experience-based consensus of the International Society for Diseases of the Esophagus.

Mucosal impedance as a diagnostic tool for gastroesophageal reflux disease: an update for clinicians

Mucosal impedance is a marker of esophageal mucosal integrity and a novel technique for assessing esophageal function and pathology. This article highlights its development and clinical application for gastroesophageal reflux disease (GERD), Barrett's esophagus, and eosinophilic esophagitis. A narrative review of key publications describing the development and use of mucosal impedance in clinical practice was conducted. A low mean nocturnal baseline impedance (MNBI) has been shown to be an independent predictor of response to anti-reflux therapy. MNBI predicts medication-responsive heartburn better than distal esophageal acid exposure time. Patients with equivocal evidence of GERD using conventional methods, with a low MNBI, had an improvement in symptoms following the initiation of PPI therapy compared to those with a normal MNBI. A similar trend was seen in a post fundoplication cohort. Strong clinical utility for the use of mucosal impedance in assessing eosinophilic esophagitis has been repeatedly demonstrated; however, there is minimal direction for application in Barrett's esophagus. The authors conclude that mucosal impedance has potential clinical utility for the assessment and diagnosis of GERD, particularly when conventional investigations have yielded equivocal results.

Assessment of laparoscopic fundoplication with endoscopy: room for improvement

INTRODUCTION

Gastroesophageal reflux disease affects a significant portion of the Australian and world population. Minimally invasive laparoscopic fundoplication is a highly effective treatment in appropriately selected patients, with a 90% satisfaction rate. However, up to 5% will undergo revisional surgery. Endoscopy is an important investigation in the evaluation of persistent or new symptoms after fundoplication. Our study sought to evaluate the inter-rater reliability and variability in assessing fundoplication with endoscopy.

METHODS

Upper gastrointestinal (UGI) surgeons and gastroenterologists were invited to join the cohort study through their professional membership with two societies based in Australia. Participants completed a two part 25-item multiple choice questionnaire, involving the analysis of ten static endoscopic images post-fundoplication.

RESULTS

A total of 101 participants were included in the study (64 UGI surgeons and 37 gastroenterologists). Over 95% of participants were consultant level, working in non-rural tertiary hospitals. Total accuracy for all 10 cases combined was 76% for UGI surgeons and 69.9% for gastroenterologists. In three of the 10 cases, UGI surgeons performed significantly better than gastroenterologists (p < 0.05). When assessing performance across each of the 4 questions for each case, UGI surgeons were more accurate than gastroenterologists in describing the integrity of the wrap (p = 0.014). Inter-rater reliability was low across both groups for most domains (kappa < 1).

CONCLUSION

Our study confirms low inter-rater reliability between endoscopists and large variations in reporting. UGI surgeons performed better than gastroenterologists in certain cases, usually when describing the integrity of the fundoplication. Our study provides further support for the use of a standardized reporting system in post-fundoplication patients.

Surgical approaches for achalasia and obesity: a systematic review and patient-level meta-analysis

PURPOSE

Synchronous and metachronous presentations of achalasia and obesity are increasingly common. There is limited data to guide the combined or staged surgical approaches to these conditions.

METHODS

A systematic review (MEDLINE, Embase, and Web of Science) and patient-level meta-analysis of published cases were performed to examine the most effective surgical approach for patients with synchronous or metachronous presentations of achalasia and obesity.

RESULTS

Thirty-three studies with 93 patients were reviewed. Eighteen patients underwent concurrent achalasia and bariatric surgery, with the most common (n = 12, 72.2%) being laparoscopic Heller's myotomy (LHM) and Roux-en-Y gastric bypass (RYGB). This combination achieved 68.9% excess weight loss and 100% remission of achalasia (mean follow-up: 3 years). Seven (6 RYGB, 1 biliopancreatic diversion) patients had bariatric surgery following achalasia surgery. Of these, all 6 RYGBs had satisfactory bariatric outcomes, with complete remission of their achalasia (mean follow-up: 1.8 years). Sixty-eight patients underwent myotomy following bariatric surgery; the majority (n = 55, 80.9%) were following RYGB. In this scenario, per-oral endoscopic myotomy (POEM) achieved higher treatment success than LHM (n = 33 of 35, 94.3% vs. n = 14 of 20, 70.0%, p = 0.021). Moreover, conversion to RYGB following a restrictive bariatric procedure during achalasia surgery was also associated with higher achalasia treatment success.

CONCLUSION

In patients with concurrent achalasia and obesity, LHM and RYGB achieved good outcomes for both pathologies. For those with weight gain post-achalasia surgery, RYGB provided satisfactory weight loss, without adversely affecting achalasia symptoms. For those with achalasia after bariatric surgery, POEM and conversion to RYGB produced greater treatment success.

Achalasia

Achalasia is a rare disorder of the oesophageal smooth muscle characterized by impaired relaxation of the lower oesophageal sphincter (LES) and absent or spastic contractions in the oesophageal body. The key pathophysiological mechanism is loss of inhibitory nerve function that probably results from an autoimmune attack targeting oesophageal myenteric nerves through cell-mediated and, possibly, antibody-mediated mechanisms. Achalasia incidence and prevalence increase with age, but the disorder can affect all ages and both sexes. Cardinal symptoms consist of dysphagia, regurgitation, chest pain and weight loss. Several years can pass between symptom onset and an achalasia diagnosis. Evaluation starts with endoscopy to rule out structural causes, followed by high-resolution manometry and/or barium radiography. Functional lumen imaging probe can provide complementary evidence. Achalasia subtypes have management and prognostic implications. Although symptom questionnaires are not useful for diagnosis, the Eckardt score is a simple symptom scoring scale that helps to quantify symptom response to therapy. Oral pharmacotherapy is not particularly effective. Botulinum toxin injection into the LES can temporize symptoms and function as a bridge to definitive therapy. Pneumatic dilation, per-oral endoscopic myotomy and laparoscopic Heller myotomy can provide durable symptom benefit. End-stage achalasia with a dilated, non-functioning oesophagus may require oesophagectomy or enteral feeding into the stomach. Long-term complications can, rarely, include oesophageal cancer, but surveillance recommendations have not been established.

Partial Fundoplication is Effective Treatment for Female Patients with Gastroesophageal Reflux and Scleroderma: A Multicenter Comparative Cohort Study

BACKGROUND

Patients with scleroderma often suffer from dysphagia and gastroesophageal reflux disease (GERD). Partial fundoplication is a validated anti-reflux procedure for GERD but may worsen dysphagia in scleroderma patients. Its utility in these patients is unknown. Here, we evaluate the efficacy and acceptability of partial fundoplication for the treatment of medically refractory GERD in patients with scleroderma.

METHODS

Analysis of a prospectively maintained database of patients who underwent fundoplication across 14 hospitals between 1991 and 2019. Perioperative outcomes, reintervention rates, heartburn, dysphagia, and patient satisfaction were assessed at 3 months, 1- and 3-years post-surgery.

RESULTS

A total of 17 patients with scleroderma were propensity score matched to 526 non-scleroderma controls. All underwent a partial fundoplication. Perioperative outcomes including complication rate, length of stay, and need for reoperation were similar between the two groups. Compared to baseline, both groups reported significantly improved heartburn at 3 months, 1- and 3-years following partial fundoplication. Surgery was equally effective at controlling heartburn across all follow-up timepoints in patients with or without scleroderma. Dysphagia to solids was more common in patients with scleroderma than controls at 3-months post-surgery, but was not significantly different to controls at 1- and 3-year follow-up. Satisfaction scores were high and comparable between both groups across all postoperative timepoints, with 100% of patients with scleroderma reporting that their initial choice to undergo surgery was correct.

CONCLUSIONS

Partial fundoplication controls reflux and is associated with a transient period of dysphagia to solids in patients with scleroderma. This approach is safe, effective and acceptable for patients with scleroderma and medically refractory GERD.

How to insert a naso-enteric tube using an ultrathin scope

Although not a technically challenging procedure, the correct insertion of a naso-enteric feeding tube is an important skill for the surgeon. The described technique has been refined over two decades, and is well tolerated, reliable and reproducible.

Five Year Follow-up of a Randomized Controlled Trial of Laparoscopic Repair of Very Large Hiatus Hernia With Sutures Versus Absorbable Versus Nonabsorbable Mesh

OBJECTIVE

To determine whether absorbable or nonabsorbable mesh repair of large hiatus hernias is followed by less recurrences at late follow-up compared to sutured repair.

SUMMARY OF BACKGROUND DATA

Radiological recurrences have been reported in up to 30% of patients after repair of large hiatus hernias, and mesh repair has been proposed as a solution. Earlier trials have revealed mixed outcomes and early outcomes from a trial reported previously revealed no short-term advantages for mesh repair.

METHODS

Multicentre prospective double-blind randomized controlled trial of 3 methods of hiatus hernia repair; sutures versus absorbable mesh versus nonabsorbable mesh. Primary outcome - hernia recurrence assessed by barium meal X-ray and endoscopy at 3-4 years. Secondary outcomes - clinical symptom scores at 2, 3, and 5 years.

RESULTS

126 patients were enrolled - 43 sutures, 41 absorbable mesh, and 42 nonabsorbable mesh. Clinical outcomes were obtained at 5 years in 89.9%, and objective follow-up was obtained in 72.3%. A recurrent hernia (any size) was identified in 39.3% after suture repair, 56.7% - absorbable mesh, and 42.9% - nonabsorbable mesh (P = 0.371). Clinical outcomes were similar at 5 years, except chest pain, diarrhea, and bloat symptoms which were more common after repair with absorbable mesh.

CONCLUSIONS

No advantages were demonstrated for mesh repair at up to 5 years follow-up, and symptom outcomes were worse after repair with absorbable mesh. The longer-term results from this trial do not support mesh repair for large hiatus hernias.

Serum outperforms plasma in small extracellular vesicle microRNA biomarker studies of adenocarcinoma of the esophagus

BACKGROUND

Circulating microRNAs (miRNAs) are potential biomarkers for many diseases. However, they can originate from non-disease specific sources, such as blood cells, and compromise the investigations for miRNA biomarkers. While small extracellular vesicles (sEVs) have been suggested to provide a purer source of circulating miRNAs for biomarkers discovery, the most suitable blood sample for sEV miRNA biomarker studies has not been defined.

AIM

To compare the miRNA profiles between matched serum and plasma sEV preparations to determine their suitability for biomarker studies.

METHODS

Matched serum and plasma samples were obtained from 10 healthy controls and 10 patients with esophageal adenocarcinoma. sEV isolates were prepared from serum and plasma using ExoQuick^TM and quantified using NanoSight. RNA was extracted from sEV preparations with the miRNeasy Serum/Plasma kit and profiled using the Taqman Openarray qPCR. The overall miRNA content and the expression of specific miRNAs of reported vesicular and non-vesicular origins were compared between serum and plasma sEV preparations. The diagnostic performance of a previously identified multi-miRNA biomarker panel for esophageal adenocarcinoma was also compared.

RESULTS

The overall miRNA content was higher in plasma sEV preparations (480 miRNAs) and contained 97.5% of the miRNAs found in the serum sEV preparations (412 miRNAs).The expression of commonly expressed miRNAs was highly correlated (Spearman’s R = 0.87, P < 0.0001) between the plasma and serum sEV preparations, but was consistently higher in the plasma sEV preparations. Specific blood-cell miRNAs (hsa-miR-223-3p, hsa-miR-451a, miR-19b-3p, hsa-miR-17-5p, hsa-miR-30b-5p, hsa-miR-106a-5p, hsa-miR-150-5p and hsa-miR-92a-3p) were expressed at 2.7 to 9.6 fold higher levels in the plasma sEV preparations compared to serum sEV preparations (P < 0.05). In plasma sEV preparations, the percentage of protein-associated miRNAs expressed at relatively higher levels (Ct 20-25) was greater than serum sEV preparations (50% vs 31%). While the percentage of vesicle-associated miRNAs expressed at relatively higher levels was greater in the serum sEV preparations than plasma sEV preparations (70% vs 44%). A 5-miRNA biomarker panel produced a higher cross validated accuracy for discriminating patients with esophageal adenocarcinoma from healthy controls using serum sEV preparations compared with plasma sEV preparations (AUROC 0.80 vs 0.54, P < 0.05).

CONCLUSION

Although plasma sEV preparations contained more miRNAs than serum sEV preparations, they also contained more miRNAs from non-vesicle origins. Serum appears to be more suitable than plasma for sEV miRNAs biomarkers studies.

Acceptable outcomes after fundoplication-different views are held by patients, GPs, and surgeons

Antireflux surgery aims to improve quality of life. However, whether patients and clinicians agree on what this means, and what is an acceptable outcome following fundoplication, is unknown. This study used clinical scenarios pertinent to laparoscopic fundoplication for gastroesophageal reflux to define acceptable outcomes from the perspective of patients, surgeons, and general practitioners (GPs). Patients who had previously undergone a laparoscopic fundoplication, general practitioners, and esophagogastric surgeons were invited to rank 11 clinical scenarios of outcomes following laparoscopic fundoplication for acceptability. Clinicopathological and practice variables were collated for patients and clinicians, respectively. GPs and esophagogastric surgeons additionally were asked to estimate postfundoplication outcome probabilities. Descriptive and multivariate statistical analyses were undertaken to examine for associations with acceptability. Reponses were received from 331 patients (36.4% response rate), 93 GPs (13.4% response), and 60 surgeons (36.4% response). Bloating and inability to belch was less acceptable and dysphagia requiring intervention more acceptable to patients compared to clinicians. On regression analysis, female patients found bloating to be less acceptable (OR: 0.51 [95%CI: 0.29-0.91]; P = 0.022), but dysphagia more acceptable (OR: 1.93 [95%CI: 1.17-3.21]; P = 0.011). Postfundoplication estimation of reflux resolution was higher and that of bloating was lower for GPs compared to esophagogastric surgeons. Patients and clinicians have different appreciations of an acceptable outcome following antireflux surgery. Female patients are more concerned about wind-related side effects than male patients. The opposite holds true for dysphagia. Surgeons and GPs differ in their estimation of event probability for patient recovery following antireflux surgery, and this might explain their differing considerations of acceptable outcomes.

Identification of microRNA Biomarkers of Response to Neoadjuvant Chemoradiotherapy in Esophageal Adenocarcinoma Using Next Generation Sequencing

BACKGROUND

Clinical trials report improved overall survival following neoadjuvant chemoradiotherapy in patients undergoing surgery for esophageal adenocarcinoma, with a 10-15% survival improvement. MicroRNAs (miRNAs) are small noncoding RNAs that are known to direct the behavior of cancers, including response to treatment. We investigated the ability of miRNAs to predict outcomes after neoadjuvant chemoradiotherapy.

METHODS

Endoscopic biopsies from esophageal adenocarcinomas were obtained before neoadjuvant chemoradiotherapy and esophagectomy. miRNA levels were measured in the biopsies using next generation sequencing and compared with pathological response in the surgical resection, and subsequent survival. miRNA ratios that predicted pathological response were identified by Lasso regression and leave-one-out cross-validation. Association between miRNA ratio candidates and relapse-free survival was assessed using Kaplan-Meier analysis. Cox regression and Harrell's C analyses were performed to assess the predictive performance of the miRNAs.

RESULTS

Two miRNA ratios (miR-4521/miR-340-5p and miR-101-3p/miR-451a) that predicted the pathological response to neoadjuvant chemoradiotherapy were found to be associated with relapse-free survival. Pretreatment expression of these two miRNA ratios, pretreatment tumor differentiation, posttreatment AJCC histopathological tumor regression grading, and posttreatment tumor clearance/margins were significant factors associated with survival in Cox regression analysis. Multivariate analysis of the two ratios together with pretherapy factors resulted in a risk prediction accuracy of 85% (Harrell's C), which was comparable with the prediction accuracy of the AJCC treatment response grading (77%).

CONCLUSIONS

miRNA-ratio biomarkers identified using next generation sequencing can be used to predict disease free survival following neoadjuvant chemoradiotherapy and esophagectomy in patients with esophageal adenocarcinoma.

Pattern of care for cancer of the oesophagus in a western population

BACKGROUND

Most oesophageal outcome research focuses on surgical treatment, despite most patients not undergoing surgery as they are unfit or have metastatic disease. Few studies have evaluated the patterns of care for all patients presenting with oesophageal cancer.

METHODS

All patients with oesophageal cancer, and high-grade dysplasia (HGD), presented at the South Australian state-wide upper gastrointestinal cancer multidisciplinary team from 2012 to 2015 were reviewed to determine the patterns of presentation and treatment.

RESULTS

A total of 375 patients were included. Diagnosis was adenocarcinoma in 69.6%, squamous cell carcinoma in 24.8% and HGD in 5.6%. The majority of patients presented with stages II and III disease (56.8%). A total of 51.5% were treated with curative intent, with 28.8% undergoing surgery and/or neoadjuvant therapy. Treatment was palliative in 48.5%, with chemoradiotherapy utilized in 20.8%. Disease stage and age impacted treatment intent. All patients with HGD received curative treatment versus 89.7%/63.8%/1% of patients with stage I/II and III/IV disease, respectively. A total of 56.9% of patients <80 years received curative treatment versus 25% of those >80 years old.

CONCLUSION

Whilst approximately half of patients underwent treatment with curative intent, only a minority underwent surgery. Future efforts to improve survival outcomes for oesophageal cancer should address patients who are unfit for surgery and those presenting with metastatic disease.

Hybrid 99mTc-magnetite tracer for dual modality sentinel lymph node mapping

Accuracy of sentinel lymph node identification using radioactive tracers in non-superficial cancers can be limited by radiation shine through and low spatial resolution of detection systems such as intraoperative gamma probes. By utilising a dual radioactive/magnetic tracer, sensitive lymphoscintigraphy can be paired with high spatial resolution intraoperative magnetometer probes to improve the accuracy of sentinel node detection in cancers with complex multidirectional lymphatic drainage. Dextran-coated magnetite nanoparticles (33 nm mean hydrodynamic diameter) were labelled with ^99mTc and applied as a lymphotropic tracer in small and large animal models. The dual tracer could be radiolabelled with 98 ± 2% efficiency after 10 min of incubation at room temperature. Biodistribution studies of the tracer were conducted in normal rats (subdermal and intravenous tail delivery, n = 3) and swine (subdermal hind limb delivery, n = 5). In rats the dual tracer migrated through four tiers of lymph node, 20 min after subdermal injection. Results from intravenous biodistribution test for radiocolloids demonstrated no aggregation in vivo, however indicated the presence of some lower-molecular weight radioactive impurities (^99mTc-dextran). In swine, the dual tracer could be effectively used to map lymphatic drainage from hind hoof to popliteal and inguinal basins using intraoperative gamma and magnetometer probes. Of the eight primary nodes excised, eight were positively identified by gamma probe and seven by magnetometer probe. The high-purity dual tracer shows early promise for sentinel node identification in complex lymphatic environments by combining sensitive preoperative lymphoscintigraphy with a high-resolution intraoperative magnetometer probe.

Validation of a risk prediction model for Barrett's esophagus in an Australian population

Background

Esophageal adenocarcinoma is a disease that has a high mortality rate, the only known precursor being Barrett's esophagus (BE). While screening for BE is not cost-effective at the population level, targeted screening might be beneficial. We have developed a risk prediction model to identify people with BE, and here we present the external validation of this model.

Materials and methods

A cohort study was undertaken to validate a risk prediction model for BE. Individuals with endoscopy and histopathology proven BE completed a questionnaire containing variables previously identified as risk factors for this condition. Their responses were combined with data from a population sample for analysis. Risk scores were derived for each participant. Overall performance of the risk prediction model in terms of calibration and discrimination was assessed.

Results

Scores from 95 individuals with BE and 636 individuals from the general population were analyzed. The Brier score was 0.118, suggesting reasonable overall performance. The area under the receiver operating characteristic was 0.83 (95% CI 0.78-0.87). The Hosmer-Lemeshow statistic was p=0.14. Minimizing false positives and false negatives, the model achieved a sensitivity of 74% and a specificity of 73%.

Conclusion

This study has validated a risk prediction model for BE that has a higher sensitivity than previous models.

Development of a risk prediction model for Barrett's esophagus in an Australian population

Esophageal adenocarcinoma has poor 5-year survival rates. Increased survival might be achieved with earlier treatment, but requires earlier identification of the precursor, Barrett's esophagus. Population screening is not cost effective, this may be improved by targeted screening directed at individuals more likely to have Barrett's esophagus. To develop a risk prediction tool for Barrett's esophagus, this study compared individuals with Barrett's esophagus against population controls. Participants completed a questionnaire comprising 35 questions addressing medical history, symptom history, lifestyle factors, anthropomorphic measures, and demographic details. Statistical analysis addressed differences between cases and controls, and entailed initial variable selection, checking of model assumptions, and establishing calibration and discrimination. The area under the curve (AUC) was used to assess overall accuracy. One hundred and twenty individuals with Barrett's esophagus and 235 population controls completed the questionnaire. Significant differences were identified for age, gender, reflux history, family reflux history, history of hypertension, alcoholic drinks per week, and body mass index. These were used to develop a risk prediction model. The AUC was 0.82 (95% CI 0.78-0.87). Good calibration between predicted and observed risk was noted (Hosmer-Lemeshow test P = 0.67). At the point minimizing false positives and false negatives, the model achieved a sensitivity of 84.96% and a specificity of 66%. A well-calibrated risk prediction model with good discrimination has been developed to identify patients with Barrett's esophagus. The model needs to be externally validated before consideration for clinical practice.

Risk factors for delayed gastric emptying following laparoscopic repair of very large hiatus hernias

Background

Delayed gastric emptying can complicate surgery for hiatus hernia. The aim of this study was to quantify its incidence following laparoscopic repair of very large hiatus hernias, identify key risk factors for its occurrence and determine its impact on clinical outcomes.

Methods

Data collected from a randomized trial of patients who underwent laparoscopic mesh versus sutured repair of very large hiatus hernias (more than 50 per cent of stomach in chest) were analysed retrospectively. Delayed gastric emptying was defined as endoscopic evidence of solid food in the stomach after fasting for 6 h at 6 months after surgery.

Results

Delayed gastric emptying occurred in 19 of 102 patients (18·6 per cent). In univariable analysis, type 2 paraoesophageal hernia (relative risk (RR) 3·15, 95 per cent c.i. 1·41 to 7·06), concurrent anterior and posterior hiatal repair (RR 2·66, 1·14 to 6·18), hernia sac excision (RR 4·85, 1·65 to 14·24), 270°/360° fundoplication (RR 3·64, 1·72 to 7·68), division of short gastric vessels (RR 6·82, 2·12 to 21·90) and revisional surgery (RR 3·69, 1·73 to 7·87) correlated with delayed gastric emptying. In multivariable analysis, division of short gastric vessels (RR 6·27, 1·85 to 21·26) and revisional surgery (RR 6·19, 1·32 to 28·96) were independently associated with delayed gastric emptying. Delayed gastric emptying correlated with adverse gastrointestinal symptomatology, including higher rates of bloating, nausea, vomiting and anorexia, as well as reduced patient satisfaction with the operation and recovery.

Conclusion

Delayed gastric emptying following large hiatus hernia repair is common and associated with adverse symptoms and reduced patient satisfaction. Division of short gastric vessels and revisional surgery were independently associated with its occurrence.

Incidence of Achalasia in South Australia Based on Esophageal Manometry Findings

BACKGROUND & AIMS

Achalasia is a disorder of esophageal motility with a reported incidence of 0.5 to 1.6 per 100,000 persons per year in Europe, Asia, Canada, and America. However, estimates of incidence values have been derived predominantly from retrospective searches of databases of hospital discharge codes and personal communications with gastroenterologists, and are likely to be incorrect. We performed a cohort study based on esophageal manometry findings to determine the incidence of achalasia in South Australia.

METHODS

We collected data from the Australian Bureau of Statistics on the South Australian population. Cases of achalasia diagnosed by esophageal manometry were identified from the 3 adult manometry laboratory databases in South Australia. Endoscopy reports and case notes were reviewed for correlations with diagnoses. The annual incidence of achalasia in the South Australian population was calculated for the decade 2004 to 2013. Findings were standardized to those of the European Standard Population based on age.

RESULTS

The annual incidence of achalasia in South Australia ranged from 2.3 to 2.8 per 100,000 persons. The mean age at diagnosis was 62.1 ± 18.1 years. The incidence of achalasia increased with age (Spearman rho, 0.95; P < .01). The age-standardized incidence ranged from 2.1 (95% CI, 1.8-2.3) to 2.5 (95% CI, 2.2-2.7).

CONCLUSIONS

Based on a cohort study of esophageal manometry, we determined the incidence of achalasia in South Australia to be 2.3 to 2.8 per 100,000 persons and to increase with age. South Australia's relative geographic isolation and the population's access to manometry allowed for more accurate identification of cases than hospital code analyses, with a low probability of missed cases.

Venous thromboembolism in patients with esophageal or gastric cancer undergoing neoadjuvant chemotherapy

There is a well-established link between cancer and venous thromboembolism (VTE), and patients receiving chemotherapy for esophageal or gastric cancer appear at high risk of developing VTE. The incidence of VTE in the neoadjuvant setting in these patients is poorly understood, as is the role for thromboprophylaxis during neoadjuvant chemotherapy. A PubMed search was conducted using a combination of terms including; esophageal & gastric cancer, deep venous thrombosis (DVT), VTE, neoadjuvant, chemotherapy and chemoradiotherapy. One hundred and fifty-four articles were retrieved and a narrative review was conducted. For patients with esophageal and gastric cancer the incidence of VTE ranged from 4 to 19%. Gastric cancer (Odds Ratio [OR] 6.38, [95% CI: 1.96-20.80]) and Stage III/IV disease, (OR 5.16 [95% CI: 1.29-20.73]) were identified as risk factors for developing VTE. Neoadjuvant chemotherapy was identified as an independent risk factor for developing VTE. Symptomatic and asymptomatic VTE have a similar effect on mortality. Median overall survival for asymptomatic VTE was 13.9 months (95% CI: 5.0-∞) versus 12.8 months (95% CI: 4.7-30.3) if the VTE was symptomatic. Neoadjuvant chemotherapy is a significant risk factor for VTE in patients with esophageal and gastric cancer. Intervention to minimize the risk using pharmacological and mechanical thromboprophylaxis should be considered, and this should start in the neoadjuvant period.

Evaluation of outcome after cardiomyotomy for achalasia using the Chicago classification

Background

Achalasia can be subdivided into manometric subtypes according to the Chicago classification. These subtypes are proposed to predict outcome after treatment. This hypothesis was tested using a database of patients who underwent laparoscopic Heller's cardiomyotomy with anterior fundoplication.

Methods

All patients who underwent Heller's cardiomyotomy for achalasia between June 1993 and March 2015 were identified from an institutional database. Manometry tracings were retrieved and re-reported according the Chicago classification. Outcome was assessed by a postal questionnaire, and designated a success if the modified Eckardt score was 3 or less, and the patient had not undergone subsequent surgery or pneumatic dilatation. Difference in outcome after cardiomyotomy was analysed with a mixed-effects logistic regression model.

Results

Sixty, 111 and 24 patients had type I, II and II achalasia respectively. Patients with type III achalasia were more likely to be older than those with type I or II (mean age 63 versus 50 and 49 years respectively; P = 0·001). Some 176 of 195 patients returned questionnaires after surgery. Type III achalasia was less likely to have a successful outcome than type II (odds ratio (OR) 0·38, 95 per cent c.i. 0·15 to 0·94; P = 0·035). There was no significant difference in outcome between types I and II achalasia (II versus I: OR 0·87, 0·47 to 1·60; P 0·663). The success rate at 3-year follow-up was 69 per cent (22 of 32) for type I, 66 per cent (33 of 50) for type II and 31 per cent (4 of 13) for type III.

Conclusion

Type III achalasia is a predictor of poor outcome after cardiomyotomy. There was no difference in outcome between types I and II achalasia.

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.

Molecular physiognomies and applications of adipose-derived stem cells

Adipose-derived stromal/stem cells (ASC) are multipotent with abilities to differentiate into multiple lineages including connective tissue and neural cells. Despite unlimited opportunity and needs for human and veterinary regenerative medicine, applications of adipose-derived stromal/stem cells are at present very limited. Furthermore, the fundamental biological factors regulating stemness in ASC and their stable differentiation into other tissue cells are not fully understood. The objective of this review was to provide an update on the current knowledge of the nature and isolation, molecular and epigenetic determinants of the potency, and applications of adipose-derived stromal/stem cells, as well as challenges and future directions. The first quarter of the review focuses on the nature of ASC, namely their definition, origin, isolation and sorting methods and multilineage differentiation potential, often with a comparison to mesenchymal stem cells of bone marrow. Due to the indisputable role of epigenetic regulation on cell identities, epigenetic modifications (DNA methylation, chromatin remodeling and microRNAs) are described broadly in stem cells but with a focus on ASC. The final sections provide insights into the current and potential applications of ASC in human and veterinary regenerative medicine.

Outcome for Asymptomatic Recurrence Following Laparoscopic Repair of Very Large Hiatus Hernia

BACKGROUND

Radiological follow-up following repair of large hiatus hernias have identified recurrence rates of 20-30%, although most are small and asymptomatic. Whether patients will eventually develop clinical problems is uncertain. This study evaluated the outcome for individuals identified with an asymptomatic hiatus hernia following previous repair vs. asymptomatic controls.

METHODS

One hundred fifteen asymptomatic patients who had previously undergone sutured repair of a large hiatus hernia and then underwent barium meal X-ray 6-60 months after surgery within a clinical trial were identified and divided into two cohorts: with (n = 41) vs. without (n = 74) an asymptomatic hernia. Heartburn, dysphagia, and satisfaction with surgery were assessed prospectively using a standardized questionnaire applying analogue scales. Consumption of antisecretory medication and revision surgery were also determined. To determine the natural history of asymptomatic recurrent hiatus hernia, outcomes for the two groups were compared at 1 and 5 years and at most recent (late) follow-up.

RESULTS

Outcomes were available at 1 year for 98.2% and 5 years or the latest follow-up (range 6-237 months) for 100%. Heartburn and dysphagia scores were low and satisfaction scores high in both groups at all follow-up points, but heartburn scores and medication use were higher in the recurrent hernia group. At late follow-up, 94.6% of the recurrent hernia group vs. 98.5% without a hernia regarded their original decision for surgery to be correct. Two patients in recurrent hernia group underwent revision surgery.

CONCLUSIONS

Patients with an initially asymptomatic recurrent hiatus hernia are more likely to report heartburn and use antisecretory medication at later follow-up than controls. However, overall clinical outcomes remain good, with high satisfaction and low surgical revision rates. Additional interventions to reduce the risk of recurrence might not be warranted.

Novel handheld magnetometer probe based on magnetic tunnelling junction sensors for intraoperative sentinel lymph node identification

Using magnetic tunnelling junction sensors, a novel magnetometer probe for the identification of the sentinel lymph node using magnetic tracers was developed. Probe performance was characterised in vitro and validated in a preclinical swine model. Compared to conventional gamma probes, the magnetometer probe showed excellent spatial resolution of 4.0 mm, and the potential to detect as few as 5 μg of magnetic tracer. Due to the high sensitivity of the magnetometer, all first-tier nodes were identified in the preclinical experiments, and there were no instances of false positive or false negative detection. Furthermore, these preliminary data encourage the application of the magnetometer probe for use in more complex lymphatic environments, such as in gastrointestinal cancers, where the sentinel node is often in close proximity to other non-sentinel nodes, and high spatial resolution detection is required.

Proximal anastomosis using the OrVil circular stapler in major upper gastrointestinal surgery

Anastomoses in major upper gastrointestinal surgery can be technically demanding, especially handsewn anastomoses traversing the diaphragmatic hiatus. The OrVil stapler is a unique circular stapler that allows rapid creation of various upper gastrointestinal anastomoses in technically challenging circumstances, particularly if additional proximal clearance is desirable. Little is reported in the literature regarding its outcomes and complication rates. In this 'How I do It' article, we describe our technique and experience with the OrVil in major upper gastrointestinal surgery.

Sentinel lymph node biopsy in esophageal cancer: an essential step towards individualized care

Lymph node status is the most important prognostic factor in esophageal cancer. Through improved detection of lymph node metastases, using the sentinel lymph node concept, accurate staging and more tailored therapy may be achieved. This review article outlines two principle ways in which the sentinel lymph node concept could dramatically influence current standard of care for patients with esophageal cancer. We discuss three limitations to universal acceptance of the technique, and propose next steps for increasing enthusiasm amongst physicians and surgeons including the development of a universal tracer, and improved contrast agents with novel dual-modality 'visibility'.

Clinical relevance of novel imaging technologies for sentinel lymph node identification and staging

The sentinel lymph node (SLN) concept has become a standard of care for patients with breast cancer and melanoma, yet its clinical application to other cancer types has been somewhat limited. This is mainly due to the reduced accuracy of conventional SLN mapping techniques (using blue dye and/or radiocolloids as lymphatic tracers) in cancer types where lymphatic drainage is more complex, and SLNs are within close proximity to other nodes or the tumour site. In recent years, many novel techniques for SLN mapping have been developed including fluorescence, x-ray, and magnetic resonant detection. Whilst each technique has its own advantages/disadvantages, the role of targeted contrast agents (for enhanced retention in the SLN, or for immunostaging) is increasing, and may represent the new standard for mapping the SLN in many solid organ tumours. This review article discusses current limitations of conventional techniques, limiting factors of nanoparticulate based contrast agents, and efforts to circumvent these limitations with modern tracer architecture.

Outcomes for trainees vs experienced surgeons undertaking laparoscopic antireflux surgery - is equipoise achieved?

BACKGROUND

There is a learning curve associated with laparoscopic antireflux surgery which has an impact on patient outcomes. It is unclear, however, whether this can be eliminated by supervision of early cases by experienced surgeons. The aim of this study was to evaluate the impact of training under supervision on outcomes for laparoscopic fundoplication.

METHOD

Patients undergoing primary laparoscopic antireflux surgery from 1995 to 2009 were identified from a prospective database. Patients were classified according to whether they were operated on by an experienced consultant or supervised trainee, and sub-categorised according to the presence of a very large hiatus hernia. A standardised questionnaire was used to assess outcomes for heartburn, dysphagia and satisfaction at 1 and 5 years follow-up. Outcomes for the study groups were compared.

RESULTS

One thousand seven hundred and ten patients underwent surgery; 1,112 were operated on by consultants and 598 by trainees. The peri-operative complication rate was not different between the groups, although in patients operated on by trainees, there were increased rates of endoscopic dilatation (9 vs. 5 % p = 0.014) and re-operation (9 vs. 6 %, p = 0.031), and a lower satisfaction rate (76 vs. 82 %, p = 0.044) within 5 years of surgery. All other outcomes were similar for trainees vs. consultants.

CONCLUSION

The learning curve for laparoscopic fundoplication had a small, but statistically significant, impact on patient outcomes, with slightly lesser outcomes when surgery was undertaken by trainees, even when supervised by experienced surgeons. Although the differences were not large, they raise questions about equipoise and highlight ethical dilemmas with teaching new generations of surgeons.