Perioperative mortality in bariatric surgery: meta-analysis.

BACKGROUND: Bariatric surgery is an established treatment for severe obesity; however, fewer than 1 per cent of eligible patients undergo surgery. The perceived risk of surgery may contribute to the low uptake. The aim of this study was to determine perioperative mortality associated with bariatric surgery, comparing different operation types and data sources. METHODS: A literature search of Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials was conducted to identify studies published between 1 January 2014 and 31 July 2020. Inclusion criteria were studies of at least 1000 patients reporting short-term mortality after bariatric surgery. Data were collected on RCTs. Meta-analysis was performed to establish overall mortality rates across different study types. The primary outcome measure was perioperative mortality. Different operation types were compared, along with study type, in subgroup analyses. The study was registered at PROSPERO (2019: CRD 42019131632). RESULTS: Some 4356 articles were identified and 58 met the inclusion criteria. Data were available on over 3.6 million patients. There were 4707 deaths. Pooled analysis showed an overall mortality rate of 0.08 (95 per cent c.i. 0.06 to 0.10; 95 per cent prediction interval 0 to 0.21) per cent. In subgroup analysis, there was no statistically significant difference between overall, 30-day, 90-day or in-hospital mortality (P = 0.29). There was no significant difference in reported mortality for RCTs, large studies, national databases or registries (P = 0.60). The pooled mortality rates by procedure type in ascending order were: 0.03 per cent for gastric band, 0.05 per cent for sleeve gastrectomy, 0.09 per cent for one-anastomosis gastric bypass, 0.09 per cent for Roux-en-Y gastric bypass, and 0.41 per cent for duodenal switch (P < 0.001 between operations). CONCLUSION: Bariatric surgery is safe, with low reported perioperative mortality rates.

Weight loss surgery helps patients with severe obesity. This study looked at the risk of dying after weight loss surgery in over 3.6 million patients. The risk was less than 1 in 1000 (0.08 per cent). The risk was lowest for gastric band and sleeve gastrectomy, then for gastric bypasses and highest for the duodenal switch operation. This shows that weight loss surgery is safe, with a low risk of dying similar to that of other common operations.

A national survey of attitudes to research in Scottish General Surgery Trainees.

INTRODUCTION: Given the importance placed on awareness and participation in research by Speciality and Training organisations, we sought to survey Scottish trainee attitudes to exposure to research practice during training and research in or out of programme. METHODS: An online survey was distributed to core and specialist trainees in general surgery in Scotland. RESULTS: Over a 4-month period, 108 trainees (75 ST/SPRs and 33 CTs) completed the survey. In their current post, most were aware of ongoing research projects (77%) and 55% were aware of trial recruitment. Only 47% attend regular journal clubs. Most believe that they are expected to present (89%) and publish (82%) during training. Most (59%) thought that participation in research is well supported. 57% were advised to undertake time out of programme research, mostly by consultants (48%) and training committee (36%). Of the 57 with time out of programme research experience, most did so in early training (37%) or between ST3-5 (47%). 28 out of the 36 (78%) without a national training number secured one after starting research. Most undertook research in a local academic unit (80%) funded by small grants (47%) or internally (33%). Most research (69%) was clinically orientated (13/55 clinical, 25/55 translational). 56% of those completing time out of programme research obtained an MD or PhD. About 91% thought that research was relevant to a surgical career. CONCLUSIONS: Most trainees believe that research is an important part of training. Generally, most trainees are exposed to research practices including trial recruitment. However, <50% attend regular journal clubs, a pertinent point, given the current 'exit exam' includes the assessment of critical appraisal skills.

Identification and analysis of murine pancreatic islet enhancers.

AIMS/HYPOTHESIS: The paucity of information on the epigenetic barriers that are blocking reprogramming protocols, and on what makes a beta cell unique, has hampered efforts to develop novel beta cell sources. Here, we aimed to identify enhancers in pancreatic islets, to understand their developmental ontologies, and to identify enhancers unique to islets to increase our understanding of islet-specific gene expression. METHODS: We combined H3K4me1-based nucleosome predictions with pancreatic and duodenal homeobox 1 (PDX1), neurogenic differentiation 1 (NEUROD1), v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MAFA) and forkhead box A2 (FOXA2) occupancy data to identify enhancers in mouse islets. RESULTS: We identified 22,223 putative enhancer loci in in vivo mouse islets. Our validation experiments suggest that nearly half of these loci are active in regulating islet gene expression, with the remaining regions probably poised for activity. We showed that these loci have at least nine developmental ontologies, and that islet enhancers predominately acquire H3K4me1 during differentiation. We next discriminated 1,799 enhancers unique to islets and showed that these islet-specific enhancers have reduced association with annotated genes, and identified a subset that are instead associated with novel islet-specific long non-coding RNAs (lncRNAs). CONCLUSIONS/INTERPRETATIONS: Our results indicate that genes with islet-specific expression and function tend to have enhancers devoid of histone methylation marks or, less often, that are bivalent or repressed, in embryonic stem cells and liver. Further, we identify a subset of enhancers unique to islets that are associated with novel islet-specific genes and lncRNAs. We anticipate that these data will facilitate the development of novel sources of functional beta cell mass.

Anti-reflux surgery in lung transplant recipients: outcomes and effects on quality of life.

Fundoplication may improve survival after lung transplantation. Little is known about the effects of fundoplication on quality of life in these patients. The aim of this study was to assess the safety of fundoplication in lung transplant recipients and its effects on quality of life. Between June 1, 2008 and December 31, 2010, a prospective study of lung transplant recipients undergoing fundoplication was undertaken. Quality of life was assessed before and after surgery. Body mass index (BMI) and pulmonary function were followed up. 16 patients, mean ± sd age 38 ± 11.9 yrs, underwent laparoscopic Nissen fundoplication. There was no peri-operative mortality or major complications. Mean ± SD hospital stay was 2.6 ± 0.9 days. 15 out of 16 patients were satisfied with the results of surgery post fundoplication. There was a significant improvement in reflux symptom index and DeMeester questionnaires and gastrointestinal quality of life index scores at 6 months. Mean BMI decreased significantly after fundoplication (p = 0.01). Patients operated on for deteriorating lung function had a statistically significant decrease in the rate of lung function decline after fundoplication (p = 0.008). Laparoscopic fundoplication is safe in selected lung transplant recipients. Patient benefit is suggested by improved symptoms and satisfaction. This procedure is acceptable, improves quality of life and may reduce deterioration of lung function.

Targeting allograft injury and inflammation in the management of post-lung transplant bronchiolitis obliterans syndrome.

Chronic allograft dysfunction, manifesting as bronchiolitis obliterans syndrome (BOS), is the major cause of morbidity and mortality in human lung transplant recipients. While alloimmunity has a definite role, there is increasing interest in overall allograft injury and subsequent inflammation and remodeling. This review deals with nonalloimmune factors that may potentiate alloimmune injury. We discuss infection and reflux/aspiration as examples of allograft injury, which may lead to chronic loss of graft function and BOS. Surgical and nonsurgical treatments aimed at preventing these insults and improving survival are considered. The need for further evidence, including randomized-controlled trials, to evaluate the role of medical and surgical therapies is emphasized by the current literature.

Does tumor depth affect nodal upstaging in squamous cell carcinoma of the head and neck?

PURPOSE: The aim of this study was to determine whether tumor depth affects upstaging of the clinically node-negative neck, as determined by sentinel lymph node biopsy with full pathologic evaluation of harvested nodes including step-serial sectioning (SSS) and immunohistochemistry (IHC). PATIENTS AND METHODS: One hundred seventy-two patients with cT1/2 N0 squamous cell carcinoma (SCC) of the oral cavity/oropharynx undergoing primary resection and either sentinel node biopsy (SNB) or SNB-assisted neck dissection as a staging tool for the cN0 neck. Harvested nodes were examined with hematoxylin-eosin staining, SSS, and IHC. Patients upstaged by SSS/IHC were denoted pN1mi. RESULTS: One hundred one of 172 patients were staged pN0, with 71 (41%) patients upstaged. Increasing tumor depth was associated with higher likelihood of upstaging (P < .001). Tumor depth showed a positive correlation with nodal stage according to TNM classification (P < .001). Tumor depth greater than 4 mm appears to be the most appropriate cutoff for risk stratification, although tumors in the oropharynx may require a lower value. CONCLUSION: Tumor depth is an important prognostic factor for patients with SCC of the oral cavity or oropharynx. Tumors greater than 4 mm are associated with greater risk of upstaging; however, this optimum cutoff value may vary between primary tumor sites.

Immunoglobulin-like domains define the nerve growth factor binding site of the TrkA receptor.

Nerve growth factor (NGF) is involved in the development and maintenance of the nervous system. NGF binds with high affinity to the extracellular region of the tyrosine kinase receptor TrkA. This domain comprises leucine and cysteine rich motifs, followed by two immunoglobulin like (Ig-like) domains. We describe the expression and purification of recombinant Ig-like domains. Fluorescence and circular dichroism spectroscopy show that the protein is folded into a compact globular structure and contains mainly beta-sheet secondary structure. Recombinant protein binds to NGF and can inhibit NGF bioactivity both in vitro and in vivo.

Specificity in Trk receptor:neurotrophin interactions: the crystal structure of TrkB-d5 in complex with neurotrophin-4/5.

BACKGROUND: The binding of neurotrophin ligands to their respective Trk cellular receptors initiates intracellular signals essential for the growth and survival of neurons. The site of neurotrophin binding has been located to the fifth extracellular domain of the Trk receptor, with this region regulating both the affinity and specificity of Trk receptor:neurotrophin interaction. Neurotrophin function has been implicated in a number of neurological disorders, including Alzheimer's disease and Parkinson's disease. RESULTS: We have determined the 2.7 A crystal structure of neurotrophin-4/5 bound to the neurotrophin binding domain of its high-affinity receptor TrkB (TrkB-d5). As previously seen in the interaction of nerve growth factor with TrkA, neurotrophin-4/5 forms a crosslink between two spatially distant receptor molecules. The contacts formed in the TrkB-d5:neurotrophin-4/5 complex can be divided into a conserved area similar to a region observed in the TrkA-d5:NGF complex and a second site-unique in each ligand-receptor pair-formed primarily by the ordering of the neurotrophin N terminus. CONCLUSIONS: Together, the structures of the TrkB-d5:NT-4/5 and TrkA-d5:NGF complexes confirm a consistent pattern of recognition in Trk receptor:neurotrophin complex formation. In both cases, the N terminus of the neurotrophin becomes ordered only on complex formation. This ordering appears to be directed largely by the receptor surface, with the resulting complementary surfaces providing the main determinant of receptor specificity. These features provide an explanation both for the limited crossreactivity observed between the range of neurotrophins and Trk receptors and for the high-affinity binding associated with respective ligand-receptor pairs.

Microbiological profiles of sputum and gastric juice aspirates in Cystic Fibrosis patients.

Gastro-Oesophageal Reflux (GOR) is a key problem in Cystic Fibrosis (CF), but the relationship between lung and gastric microbiomes is not well understood. We hypothesised that CF gastric and lung microbiomes are related. Gastric and sputum cultures were obtained from fifteen CF patients receiving percutaneous endoscopic gastrostomy feeding. Non-CF gastric juice data was obtained through endoscopy from 14 patients without lung disease. Bacterial and fungal isolates were identified by culture. Molecular bacterial profiling used next generation sequencing (NGS) of the 16S rRNA gene. Cultures grew bacteria and/or fungi in all CF gastric juice and sputa and in 9/14 non-CF gastric juices. Pseudomonas aeruginosa(Pa) was present in CF sputum in 11 patients, 4 had identical Pa strains in the stomach. NGS data from non-CF gastric juice samples were significantly more diverse compared to CF samples. NGS showed CF gastric juice had markedly lower abundance of normal gut bacteria; Bacteroides and Faecalibacterium, but increased Pseudomonas compared with non-CF. Multivariate partial least squares discriminant analysis demonstrated similar bacterial profiles of CF sputum and gastric juice samples, which were distinct from non-CF gastric juice. We provide novel evidence suggesting the existence of an aerodigestive microbiome in CF, which may have clinical relevance.

Identification of the histidine residue in Escherichia coli isocitrate lyase that reacts with diethylpyrocarbonate.

Escherichia coli isocitrate lyase was inactivated by diethylpyrocarbonate in a pseudo-first-order process. The enzyme was completely inactivated by modification of a single histidine residue, but slower modification of further residues also occurred. The substrate, isocitrate, and products, glyoxylate and succinate, protected against inactivation by diethylpyrocarbonate but this was not simply due to binding at the active site. Treatment of the inactivated enzyme with hydroxylamine led to only partial recovery of activity. Diethylpyrocarbonate also reacted with sulphydryl groups in isocitrate lyase, as judged by titrations with Nbs2, but this reaction was not responsible for the failure of hydroxylamine to reactivate the enzyme fully. The reactivity of isocitrate lyase to diethylpyrocarbonate declined with pH, following a titration curve for a group of pKa 6.1. Isolation and sequencing of ethoxyformylated peptides showed that the major site of modification by diethylpyrocarbonate was histidine residue 306.

Effect of oral clodronate on metastatic bone pain: a double-blind, placebo-controlled study.

PURPOSE: To study the effects of oral clodronate on bone pain in patients with advanced metastatic bone disease. PATIENTS AND METHODS: Fifty-five patients with progressing bone metastases were randomized to receive oral clodronate 1,600 mg/d (n = 27) or matching placebo (n = 28). The main outcome measures were bone pain (visual analog score), analgesic use, and compliance with therapy. RESULTS: Visual analog pain score (median [interquartile range]) decreased from the pretreatment value in the clodronate group (-0.9 [-2.6 to -0.4]), but increased in the placebo group (+0.4 [-1.0 to +4.0]) (P = .03 between groups). Analgesic use increased with disease progression to a similar extent in both groups (59% increased use in the clodronate group v 64% of placebo group; difference not significant). Ten patients (37%) in the clodronate group and 12 (46%) in the placebo group withdrew from the study prematurely, most often because of difficulty with swallowing the capsules. CONCLUSION: Clodronate improved control of bone pain to a modest degree in patients with advanced metastatic cancer, but did not reduce analgesic requirement significantly. Perhaps as a result of these factors, it proved difficult to maintain patients on therapy. Further studies will be needed to define the role of bisphosphonates such as clodronate in this situation, in comparison with established treatments such as radiotherapy and analgesics.

Prevention of graft-versus-host disease by ex vivo T cell depletion: reduction in graft failure with augmented total body irradiation.

Graft-versus-host disease prevention was attempted in 35 consecutive patients with hematological malignancy who received bone marrow from an HLA match sibling donor who was depleted of T cells ex vivo. Five of the first 8 patients who received cyclophosphamide 60 mg/kg on 2 consecutive days followed by fractionated total body irradiation (TBI) (6 x 2 Gy) had graft failure. The subsequent 27 patients had received an extra fraction of TBI (7 x 2 Gy), and only one failed to have stable engraftment. There were no differences in nucleated cell dose, granulocyte-macrophage colony-forming units, or T cell numbers given to the two groups. Neutrophil but not platelet regeneration of those patients who successfully grafted was slower than in a group of historical controls receiving unmanipulated marrow. Significant graft-versus-host disease was prevented with no increase in relapse rate. We suggest that engraftment can be reliably achieved by augmenting the TBI conditioning in recipients of T cell-depleted matched allogeneic bone marrow.

A phase I study of Onyx-015, an E1B attenuated adenovirus, administered intratumorally to patients with recurrent head and neck cancer.

An E1B 55 kDa gene-deleted adenovirus, Onyx-015, which reportedly selectively replicates in and lyses p53-deficient cells, was administered by a single intratumoral injection to a total of 22 patients with recurrent head and neck cancer. The objectives of this Phase I study were to determine the safety, feasibility, and efficacy of this therapy and determine any correlation to p53 status. Six cohorts were investigated with a dose escalation from 10(7)-10(11) plaque-forming units. Toxicity was assessed using NCIC criteria. Tumor response was assessed by clinical and radiological measurement. Blood samples were taken to detect adenovirus DNA and neutralizing antibody to adenovirus. Tumor biopsies were taken to detect adenovirus by in situ hybridization. Treatment was well tolerated, with the main toxicity being grade 1/2 flu-like symptoms. Dose-limiting toxicity was not reached at the highest dose of 10(11) plaque-forming units. Twenty-one of the 22 patients treated showed an increase in neutralizing antibody to adenovirus. In situ hybridization showed viral replication in 4 of 22 patients treated, all of whom had mutant p53 tumors. Using conventional response criteria, no objective responses were observed. However, magnetic resonance imaging scans were suggestive of tumor necrosis at the site of viral injection in five patients, three of whom were classified using nonconventional criteria as partial responders, and two of whom were classified using nonconventional criteria as minor responders. Of these five cases, four had mutant p53 tumors. The response duration for the three partial responders was 4, 8, and 12 weeks. An additional eight patients had stable disease in the injected tumors lasting from 4-8 weeks. These preliminary results show that intratumoral administration of Onyx-015 is feasible, well tolerated, and associated with biological activity. Further investigation of Onyx-015, particularly with a more frequent injection protocol and in combination with systemic chemotherapy, is warranted.

National survey on endoscopy training in the UK.

INTRODUCTION: Gastrointestinal (GI) endoscopy is an important skill for both gastroenterologists and general surgeons but concerns have been raised about the provision and delivery of training. This survey aimed to evaluate and compare the delivery of endoscopy training to gastroenterology and surgical trainees in the UK. METHODS: A nationwide electronic survey was carried out of UK gastroenterology and general surgery trainees. RESULTS: There were 216 responses (33% gastroenterologists, 67% surgeons). Gastroenterology trainees attended more non-training endoscopy lists (mean: 3.0 vs 1.2) and training lists than surgical trainees (mean: 0.9 vs 0.5). A significantly higher proportion of gastroenterologists had already achieved accreditation in gastroscopy (60.8% vs 28.9%), colonoscopy (66.7% vs 1.4%) and flexible sigmoidoscopy (33.3% vs 3.0%). More gastroenterology trainees aspired to achieve accreditation in gastroscopy (97.2% vs 79.2%), flexible sigmoidoscopy (91.7% vs 70.1%) and colonoscopy (88.8% vs 55.5%) by completion of training. By completion of training, surgeons were less likely than gastroenterologists to have completed the required number of procedures to gain accreditation in gastroscopy (60.3% vs 91.3%), flexible sigmoidoscopy (64.6% vs 68.6%) and colonoscopy (60.3% vs 70.3%). CONCLUSIONS: This survey highlights marked disparities between surgical and gastroenterology trainees in both aiming for and achieving accreditation in endoscopy. Without changes to the delivery and provision of training as well as clarification of the role of endoscopy training in a surgical training programme, future surgeons will not be able to perform essential endoscopic assessment of patients as part of their management algorithm.

A national trainee-led audit of inguinal hernia repair in Scotland.

PURPOSE: This audit assessed inguinal hernia surgery in Scotland and measured compliance with British Hernia Society Guidelines (2013), specifically regarding management of bilateral and recurrent inguinal hernias. It also assessed the feasibility of a national trainee-led audit, evaluated regional variations in practise and gauged operative exposure of trainees. METHODS: A prospective audit of adult inguinal hernia repairs across every region in Scotland (30 hospitals in 14 NHS boards) over 2-weeks was co-ordinated by the Scottish Surgical Research Group (SSRG). RESULTS: 235 patients (223 male, median age 61) were identified and 96 % of cases were elective. Anaesthesia was 91 % general, 5 % spinal and 3 % local. Prophylactic antibiotics were administered in 18 %. Laparoscopic repair was used in 33 % (30 % trainee-performed). Open repair was used in 67 % (42 % trainee-performed). Elective primary bilateral hernia repairs were laparoscopic in 97 % while guideline compliance for an elective recurrence was 77 %. For elective primary unilateral hernias, the use of laparoscopic repair varied significantly by region (South East 43 %, North 14 %, East 7 % and West 6 %, p < 0.001) as did repair under local anaesthesia for open cases (North 21 %, South East 4 %, West 2 % and East 0 %, p = 0.001). Trainees independently performed 9 % of procedures. There were no significant differences in trainee or unsupervised trainee operator rates between laparoscopic and open cases. Mean hospital stay was 0.7-days with day case surgery performed in 69 %. CONCLUSIONS: This trainee-lead audit provides a contemporary view of inguinal hernia surgery in Scotland. Increased compliance on recurrent cases appears indicated. National re-audit could ensure improved adherence and would be feasible through the SSRG.

Changes in the incidence and mortality of testicular cancer in Scotland with particular reference to the outcome of older patients treated for non-seminomatous germ cell tumours.

This paper describes the temporal pattern of germ cell testicular cancer in Scotland between 1960 and 1990. The effect of age on the prognosis of patients with non-seminomatous germ cell tumours (NSGCT) has been assessed by studying all patients presenting in the West of Scotland between 1975 and 1989. Between 1960 and 1990, the number of testicular germ cell tumours registered has increased more than 2-fold; mortality rates have declined equally dramatically. Univariate and multivariate analysis of the data obtained on 440 patients with NSGCT showed age was not a prognostic factor influencing survival. 52 were patients over 40 years at presentation; their 5 years survival was 71% compared with 79% in the younger patients (n = 388). This small survival difference is probably explained by the higher proportion of older patients treated before 1980. Treatment for this older group should be approached with the same curative intent as for younger patients and the same expectation of success.