Scientific surgery

Article Review

Lanik WE, Luke CJ, Nolan LS, et al. Microfluidic device facilitates in vitro modeling of human neonatal necrotizing enterocolitis-on-a-chip. JCI Insight. 2023;8(8):e146496.

Necrotizing enterocolitis (NEC) is a severe, potentially fatal disease seen in premature neonates that results in intestinal injury and necrosis.¹ The pathophysiology of NEC is based on loss of intestinal barrier integrity, translocation of bacteria across the gut barrier, and sepsis. The use of in vitro models is important to accelerate NEC research, given the shortage of surgically obtained samples from preterm neonates. The main limitation of currently available monotypic epithelial cell line in vitro models is the inaccurate simulation of the multiple cell types and complex intestinal dysbiosis implicated in NEC.² On the other hand, the available intestinal organoid models can differentiate subtypes of intestinal epithelial cell and have apical-basolateral polarity within a three-dimensional spherical architecture. The limitation is the inability to assess the effect of microbial interactions or therapeutics on the apical epithelial surface.³ Notably, advances in microfluidic technology have led to the development of intestine-on-a-chip models that can simulate the human small intestine microenvironment through cellular differentiation, formation of three-dimensional villus-like axes, mucus production, continuous luminal flow, and mimicry of peristalsis.⁴

The article by Lanik et al.⁵ describes the development of a novel NEC-on-a-Chip model by a combination of premature infant small intestinal enteroids cocultured with human intestinal

microvascular endothelial cells and patient-derived microbiota. This recreates critical features of premature gut pathophysiology, including microbial dysbiosis, to simulate the pathophysiology of the human disease NEC. The authors initially demonstrated the feasibility of creating a Neonatal-Intestine-on-a-Chip model using enteroids derived from neonatal small intestine surgically resected for noninflammatory intestinal conditions that were dissociated and seeded into the Matrigel-coated microfluidic device. They showed that the Neonatal-Intestine-on-a-Chip model was similar to human small intestine by demonstrating the similarity of villus-like architecture, cell-cell adhesions, and epithelial cell apical-basolateral polarity using immunostaining.

Additionally, the authors were able to show that the gene expression in human NEC disease is associated with decreased number of stem cell, Paneth cell, and goblet cell markers, upregulation of interleukin 1β and interleukin 8, as well as reduction in the expression of proliferation markers Ki67 and proliferating cell nuclear antigen. Subsequently, they isolated the intestinal microbiome from the intestine of a premature infant that died from severe NEC and added it to their Neonatal-Intestine-on-a-Chip model to generate a NEC-on-a-Chip model and were able to show similar differences when comparing NEC-on-a-Chip to either human intestine or Neonatal-Intestine-on-a-Chip controls. Additionally, the authors were able to demonstrate the similarities between NEC-on-a-Chip and human NEC by showing a decrease in number of goblet, Paneth, and enteroendocrine cells, along with a reduction in proliferation marker Ki67 for both, compared to their respective controls of Neonatal-Intestine-on-a-Chip and healthy neonatal intestinal tissue, respectively. Then, the authors reported the effect of microbial dysbiosis on epithelial barrier dysfunction and gradually increasing permeability over 72 hours following intestinal bacteria exposure via evidence of decreased expression of an epithelial tight junction marker in the NEC-on-a-Chip model compared to control chips. Last but not least, the authors showed similar gene expression profiling in NEC-on-a-Chip and human NEC disease via RNA-sequencing, that demonstrated upregulated pathways related to inflammation and cellular death when compared to controls.

The authors concluded that the in vitro NEC-on-a-Chip model is similar in many aspects to in vivo human NEC disease, it allows study of the pathophysiology of NEC, and testing possible therapeutics, and can pave the way towards personalized medicine for NEC given the ability to produce patient-specific intestinal epithelium.

Despite the significance and novelty of the article by Lanik et al.⁵, there are certain limitations worth mentioning. Although the authors were able to produce three-dimensional villus-like structures, they lacked elements of complexity associated with intestinal villi in vivo,such as immune cells, lymphatics, and systemic circulation. Moreover, these were models developed under aerobic conditions without the influence of anaerobic microenvironment existing in the human intestine. Finally, due to the shortage of surgically obtained human intestine samples, the derived epithelial cells need to be expanded via in vitro models for further use that may lead to changes in gene and protein expression.

In conclusion, NEC is a significant cause of premature infant morbidity and mortality, and thus efforts to further the understanding of disease pathophysiology and novel therapeutics are of outmost importance. The development of NEC-on-a-Chip models using standardized protocols has revolutionized the field of NEC research and allows for large-scale approaches, such as drug and therapy screening. Future endeavors should focus on overcoming the inherent limitations of such models by using co-culture systems trying to imitate the immunological and microbiological components of the intestine that are implicated in the development of NEC.

Measuring the impact of social media engagement is a nuanced task, with an array of metrics in play. Among these metrics, impressions stand out as a valuable surrogate indicator. Impressions quantify the total number of times a post appears on a user’s screen, offering insights into content’s potential reach and visibility.

Spotlight on the Top Twenty Posts

To illuminate the most influential posts from @BJSurgery, @BJSOpen, and @BJSAcademy, we’ve meticulously curated the top twenty posts from their August activity. Our selection criteria zero in on posts that achieved the highest number of impressions* on August 8th, as meticulously monitored and documented by X analytics for each individual post.

Without further ado, let’s embark on the BJS Top Twenty countdown:

Number 20 – 9019 impressions

On Aug 10, @BJSurgery “Leading article” on oesophageal anastomotic leaks:

Number 19 – 9228 impressions

A @BJSSurgery post sharing a “Gloves off” debate on oesophagectomy on Aug 16:

Number 18 – 9497 impressions

@BJSAcademy announced the “How to write a paper” course and that the “How to review a paper” is coming soon on Aug 19:

Number 17 – 9516 impressions

On Aug 16, @YoungBJS article posted by @BJSurgery about splenic injury from blunt trauma:

Number 16 – 9635 impressions

Six days later, Aug 22, @BJSAcademy shared a podcast and article on how to write a plain English abstract:

Number 15 – 9777 impressions

Early in the month, Aug 4, @BJSurgery posted a paper on timing for rectal surgery after short-course radiotherapy:

Number 14 – 10.2K impressions

A paper reporting the results of a network meta-analysis of RCTs comparing bariatric surgery and glucose-lowering agents for type 2 diabetes and obesity, shared by @BJSOpen on Aug 14:

Number 13 – 10.6K impressions

On Aug 28, @BJSOpen posted the most recent systematic review on quality of life after severe acute pancreatitis:

Number 12 – 11.1K impressions

A retrospective analysis of the surgical treatment of hilar cholangiocarcinoma posted by @BJSOpen for days earlier that Number 13:

Number 11 – 11.2K impressions

@BJSurgery congratulated Aneel Banghu on X on Aug 29 for his Guinness World Record certificate for the article with the most authors, 1525:

Number 10 – 12.3K impressions

@BJSurgery presented “The instrumentalist” post on scissors on Aug 11:

Number 9 – 12.5K impressions

On Aug 15, @BJSOpen shared a paper reporting a comprehensive assessment of the management of acute cholecystitis in Scotland:

Number 8 – 12.9K impressions

@BJSurgery posted an editorial on AI and scientific writing on Aug 9, which was authored by @DesWinter and @AbeLaparoscopy:

Number 7 – 13.2K impressions

On Aug 13, @BJSOpen conducted a poll about bariatric surgery, drugs, and HbA1c reduction. You invite you to check the results:

Number 6 – 14.3K impressions

@BJSOpen shared an #openaccess paper on the implementation of a quadruple intraoperative anastomotic assessment (4-Check) during transanal TME for rectal cancer on Aug 8:

Number 5 – 14.3K impressions

On Aug 11, @BJSurgery posted a “short report” on the oncological outcomes of pancreatectomy with arterial resection:

Number 4 – 14.3K impressions

@BJSOpen posted an #openaccess paper on the outcome of oncologic patients who received perioperative allogeneic blood transfusions on Aug 21, citing the Number 2 post:

Number 3 – 15.4K impressions

On Aug 27, a popular @BJSOpen poll was posted. It was about factors that decrease the quality of life of patients with severe acute pancreatitis:

Number 2 – 17.5K impressions

Another @BJSOpen poll posted on Aug 20 and related to the influence of perioperative allogeneic blood transfusions on long-term outcomes following surgery for gastric and colorectal cancer:

Finally, the Number 1 BJS Top Twenty post on X with 25K impressions is from @BJSOpen on Aug 19: a systematic review and network meta-analysis of RCTs that determined the optimal preoperative bowel preparation strategy in elective colorectal surgery:

*In cases where two posts shared an identical number of impressions, we prioritized the more recent post as having a higher impression count.

Tan J, Ryan EJ, Davey MG, McHugh FT, Creavin B, Whelan MC et al.

BJS Open 2023; 7: zrad040.

A total of 60 RCTs was included in the analysis. Optimal results were achieved with or without mechanical bowel preparation, but with intravenous antibiotics and oral antibiotics.

Comment: Perhaps the final word, and interesting that antibiotics were more important than bowel preparation.

Balzano G, Zerbi A, Aleotti F, Capretti G, Melzi R, Pecorelli N et al.

Ann Surg 2023; 277: 894-903.

Total pancreatectomy (TP) was associated with reduced perioperative morbidity: 60 versus 90.3%, P=0.008, and similar hospital stay, in this study that included 61 procedures. Survival rates were also similar, but TP was associated with a higher risk of diabetes.

Comment: Intriguing, and could lead to a change in standard care.

Santos A, Mentula P, Pinta T, Ismail S, Rautio T, Juusela R et al.

JAMA Surg 2023; 158: 593-601. 

Eighty-five patients were included in this planned analysis. After two years, 25/44 patients in the conservative group had recurrent diverticulitis and eight required sigmoid colectomy. Four patients who had surgery had recurrent diverticulitis. G.I. quality of life was similar between the two groups.

Comment: Useful interim information.

Molenaar CJL, Minnella EM, Coca-Martinez M, ten Cate DWG, Regis M, Awasthi R et al, for the PREHAB Study Group.

JAMA Surg 2023; 158: 572-581.

The study included 251 participants, who mostly had laparoscopic or robotic resection. A 4-week supervised, multimodal prehabilitation programme reduced severe postoperative complications: 17.1 versus 29.7 per cent, P=0.02. Prehabilitation generally improved functional capacity up to four weeks postoperatively.

Comment: More evidence that a good recovery from surgery starts well before hospital admission.

Enzmann FK, Nierlich P, Hölzenbein T, Aspalter M, Kluckner M, Hitzl W et al.

Ann Surg 2023; 277: e1208-e1214.

The study included 218 legs in 209 patients. After four years, there was no difference in patency, limb survival or complications, but patients who had a surgical bypass reported greater clinical improvement.

Comment: More fuel for the debate started by the and BESTCLI and BASIL trials.

Lu X, Jiang J, Shen Z, Chen G, NP YW, Xiao X et al.

Ann Surg 2023; 277: e1200-e1207.

A total of 200 babies with Kasai disease were randomly allocated adjuvant steroids after portoenterostomy. After six months, the proportion of babies who were jaundice-free and had avoided liver transplantation was higher in those treated with steroids: 54.1 versus 31 per cent, P=0.0015.

Comment: Should become routine care.

Fawzy A, Balbaa MA, Hagag M.

BJS Open 2023; 7: zrac173.

There was no difference in the rate of patient satisfaction between these two procedures in the 78 patients studied. Most patients in both groups considered the result excellent.

Comment: Both these new techniques are effective.

Coles CE, Haviland JS, Kirby AM, Griffin CL, Sydenham MA, Titley JC et al, on behalf of the IMPORT Trial Management Group.

Lancet 2023; 401: 2124-2137.

A total of 2617 women were enrolled in the trial. Concomitant booster irradiation was safe, with similar rates of local recurrence: 2 per cent and 3.2 per cent in the different dosages, compared to 1.9 per cent in controls. Simultaneous booster irradiation reduced patient visits.

Comment: Easier for the women, and should improve treatment scheduling.

Schrag D, Uno H, Rosovsky R, Rutherford C, Sanfilippo K, Villano JL et al, for the CANVAS Investigators.

JAMA 2023; 329: 1924-1933.

This study included 671 patients with cancer and a new episode of VTE. After six months, the risk of recurrent VTE was not inferior with oral anticoagulation (6.1per cent), compared to those receiving low molecular weight heparin (8.8 per cent). Bleeding complication rates were similar.

Comment: Reassuring, and easier for patients.

https://doi.org/10.58974/bjss/azbc027

Based on Dynamics of adipose tissue macrophage populations after gastric bypass surgery.

As stated by the authors of this paper, obesity is an epidemic worldwide and has been implicated as a central factor in the pathophysiology for the metabolic syndrome (MetS) and other chronic medical conditions. For example, obesity is a critical risk factor for the development of type 2 diabetes mellitus (T2DM) with research demonstrating obesity-driven insulin resistance (IR) in white adipose tissue (WAT) as a primary driver.^1,2 This report is significant given that our understanding of adipose tissue has changed and we now know that it is a complex, hormonally active organ. Furthermore, metabolic dysregulation of adipose tissue, as observed in obesity, leads to local inflammation which is a key component in the pathophysiology of MetS and IR.³

The immune cells most central to the development and control of adipose tissue inflammation are macrophages. In obesity, there is a significant shift in macrophage activation from an “M2” or anti-inflammatory state to an “M1” or pro-inflammatory state.⁴ Overproduction of pro-inflammatory cytokines such as TNF-α from M1 macrophages has been linked to IR while IL-10 secretion from M2 macrophages promotes insulin sensitivity.^4,5 However, there is emerging evidence that there are discrete subpopulations and activations states outside the dichotomy of M2 or M1 macrophage phenotypes which may be associated with various diseases including T2DM, cancer, atherosclerosis, etc.⁶ The expanding knowledge of macrophage diversity likely applies to adipose tissue, thus further demonstrating the complexity of adipose inflammation.^7,8

Histologically, the defining feature of adipose tissue inflammation is dead or dying adipocytes surrounded by macrophages which form crown-like structures (CLS) (Figure 1A-C).^9,10 In this study, Palomäki et al. performed a tissue sample analysis on subcutaneous fat from 122 obese subjects undergoing either surgery or conservative treatment. For comparison, they included 39 and 43 subjects with paired adipose tissue samples, respectively. To our knowledge, this is the largest follow-up tissue sample analysis involving obese subjects. Despite advances in medical therapy, bariatric surgery still remains the gold standard for treatment of severe obesity with laparoscopic Roux-en-Y gastric bypass (LRYGB) and vertical sleeve gastrectomy being the most common procedures.¹¹ However, even with its superior effect on weight loss, as pointed out by the authors, 11-35% of patients develop suboptimal weight loss. Importantly, weight loss has been associated with improvement of comorbidities and inflammatory status.^3,12,13 Two aims of this study were addressed: The first was to understand the impact of LRYGB versus conventional obesity treatment on adipose tissue inflammation by measuring macrophage distributions/populations and CLS density before and after each intervention. The second aim was to determine the extent to which inflammation correlated to weight loss.

The methods involved in this study included sampling of periumbilical subcutaneous fat from obese individuals before and at one year following the planned intervention: LRYGB or conventional treatment. Samples were prepared by standard histopathology  and immunohistochemical staining and were analyzed for both adipocyte density, fat cell size and CD68 staining to detect macrophages.¹⁴ Using imaging software, the number of macrophages within a given sample area was determined, as well as manual counting of the number of CLS within the sample.

In the samples collected prior to intervention, there were no major differences seen between the two groups in terms of mean number of CLS per 1000 fat cells. They noted that 16.6% of CD68 macrophage staining was localized to the CLS while the remainder and majority was dispersed throughout the adipose tissue. Using bivariate analysis, they also demonstrated a correlation between CLS density and CD68 staining outside of CLS. Therefore, the greater the number of CLS detected, the greater the number of CD68 staining in the surrounding tissues, correlating to a greater number of macrophages. Interestingly, in patients with obesity who also had T2DM, they observed significantly larger fat cell (FC) size with smaller FC density compared to non-diabetic patients. Prior work by others has demonstrated that FCs are larger in patients with T2DM even among those who are not obese.¹⁵ Some have hypothesized that fat cell hypertrophy may lead to local hypoxia and may serve as a stimulus of inflammation, thus serving as a basis for the white adipose tissue dysregulation.^16,17

As might be expected, at one year follow-up, BMI, weight, and total weight loss (TWL) % had declined in the surgery group, but no change was seen in the conventional treatment group. A shift from larger to smaller FC size adipocyte populations was observed in the LRYGB group but not in the conventional group.

In the surgical group, there was a statistically significant reduction in CLS per 1000 FCs while in contrast, CLS density demonstrated an increased trend in the conventional treatment group (Figure 2A). There was also an increase in CD68 positive staining outside of CLS with the conventional group without a significant change in the surgical group (Figure 2B). Impressively, the surgery group had a greater number of CD68 positive staining within CLS compared to the conservative group at baseline, but had a greater reduction after intervention, indicating reduced inflammation as a result of surgery (Figure 2C). Surgery not only resulted in a greater reduction in CLS-associated macrophages when compared to the conservatively treated group, but also demonstrated a lower overall CLS density. As stated in the manuscript, obese adipocytes are susceptible to a pyroptosis-like programmed cell death which is similar to apoptosis but is characterized by a highly inflammatory state. In pyroptosis, there is release of proinflammatory cellular contents and increased inflammasome stimulation.¹⁸ Therefore, following LRYGB, the reduction in CLS suggests a decrease in adipocyte cell death which in turn, may represent a decrease in macrophage recruitment, activation and inflammation.  

A “within-group” comparison was made in the surgical group; the investigators compared patients who had a good response (TWL >20%) to those with a poor response (TWL <20%) at 12 months. Results indicated no significant associations of the preoperative measurements with eventual weight loss. Interestingly, despite suboptimal weight loss, the TWL <20% groups demonstrated significant decreases in CLS density and CD68 staining within CLS reaching similar values to the TWL >20% group after one year.

This weight-loss independent improvement in CLS density and associated macrophages following surgery emphasizes the positive metabolic response and inflammatory changes that occur with surgery, independent of weight loss alone. Therefore, this study further confirms that there are significant metabolic effects of surgery that appear to occur independent of weight loss. For example, in obese patients with T2DM, metabolic surgery has been shown to improve the incretin effect, increase bile acid circulation and metabolism, alter the gut microbiome, and decrease adipose tissue inflammation. Taken together, there are multiple beneficial effects of surgery that may ultimately lead to improvements in glycaemic control and insulin resistance.^12,13,19,20

Limitations:

Given the lack of difference in CD68 staining outside the CLS, this study was limited in focus as it only quantitatively assessed macrophages without assessing their function qualitatively by examining, for example, their phenotype state (i.e. M1 versus M2). Therefore, whether a functional change in macrophage activity occurred as a result surgery will require further study.

Conclusions and Importance to the field of surgery:

This study represents the largest tissue-based follow-up analysis comparing patients with obesity before and after bariatric surgery versus conservative therapy at one year follow-up. The finding that there were significant decreases in CLS and associated macrophages after bariatric surgery when compared to conservative management, suggests a significant role for surgery to dampen the inflammatory state of the obese patient and perhaps maintain improved metabolic control. This is further strengthened by the observation that regardless of the degree of weight loss following surgery, all surgical patients had improvements in CLS density and associated macrophages. These findings add to the growing body of research demonstrating that weight-loss independent mechanisms after bariatric surgery contribute to the superior improvement in metabolic factors of obese patients versus conventional weight-loss therapy. This study further highlights the role of bariatric surgery in the care of obese patients.

Welcome to the July 2023 edition of the @BJSAcademy social media review!

Here, we spotlight captivating and popular posts from the BJS community accounts on X.

Continuing the #AI series on @BJSAcademy, the article “The role of artificial intelligence in diagnostic imaging” authored by Barbara Seeliger, Alexandros Karargyris, and Didier Mutter was shared on July 1st on X. This post garnered 2,204 views by Aug 14th:

Read the article here.

On July 2nd, @BJSOpen initiated a poll on X, seeking readers’ opinions on recently published impact factors, given the consistent drop in numbers. Results showed that most respondents (39.7% out of 68 votes) found the outcome as expected. Interestingly, 35.3% opined that the impact factor is overrated. By Aug 14th, the post accumulated 5,589 views:

In part 6 of the @BJSAcademy series, the article “Opportunities, functions and three wise monkeys” by Ameera AlHasan was shared on July 4th on X:

Read the article here.

On the same day, @BJSOpen posted an #openaccess article link, reporting results from a retrospective cohort study on the effects of preoperative polypharmacy or hyper-polypharmacy on surgical patient outcomes:

Read the article here.

@BJSOpen shared the paper “What’s the influence of #obesity on perioperative outcomes after gastrointestinal #surgery?” on July 11th. Surprisingly, this meta-analysis challenges assumptions about higher postoperative mortality in patients with obesity:

Read the article here.

On July 12th, @BJSurgery posted the Cutting Edge review on gut microbiota, faecal transplantation, and surgical outcomes. The post garnered 3,671 views:

Read the paper here.

Exploring the theme of efficient resource utilization and environmental sustainability, on July 13th, @BJSOpen shared the #openaccess article titled “Waste not, want not: orthopaedic waste data,” which amassed 1571 views by Aug 14th:

Read the article here.

On July 14th, @BJSurgery linked to the #openaccess article “Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases.”:

Read the article here.

The review of recent #RandomizedClinicalTrials for June was shared on X on July 19th:

Read the article here.

On July 22nd, @BJSOpen quoted a previous X post on gene signature analysis and outcome prediction in patients with early pancreatic cancer who underwent R0 resection:

Read the article here.

Interventional oncology for liver tumours was spotlighted on July 24th by @BJSAcademy in a surgical digest titled “Image-guided ablation for liver tumours.” The post garnered 3286 views by Aug 14th:

Read the article here.

Finally, on July 30th, @BJOpen posted the most-viewed post of the month on X (22.7K views). The poll questioned when surgeons perform prophylactic mesh augmentation after laparotomy, with 65.3% of 147 votes leaning towards “Never!”:

https://doi.org/10.58974/bjss/azbc026

This article highlights the close relation between the central nervous system and peripheral immune system, forming a neuroimmune axis that has clinical implications we are just beginning to understand. This article from the journal Science and Translational Medicine  couples both patient data and a mouse model of intracranial haemorrhage (ICH) to explore the influence of ICH on haematopoietic stem cells (HSC) and the subsequent impact of HSCs on the brain.

In the first experiment, bone marrow cells were harvested from skull flaps of patients requiring decompressive craniotomies for ICH and compared with cells from patients with unruptured aneurysms. In the second, ICH was induced in a mouse model by injection of autologous blood into brain parenchyma and subsequent harvest of femur bone marrow cells. Both the human and mouse data demonstrated increased myeloid progenitor cells and haematopoiesis with ICH. Adrenergic innervation through the β3 receptor on haematopoietic cells promotes production of Ly6C^low , a patrolling non-classical monocyte (NCM), in the bone marrow, which rapidly travels to the brain after ICH. Through transcriptomic analysis of the HSCs after ICH, Cdc42 (cell division cycle 42) was identified as an upregulated gene. Cdc42 was noted to be ablated in β3-adrenergic knockout mice, Adrb3-/-, linking the relationship of Cdc42 and adrenergic innervation. Treatment with a Cdc42 inhibitor led to decreased bone marrow proliferation, reduced Ly6C^low monocytes, and exacerbated brain injury. Given the role of the β3 receptor in proliferation and targeting of haematopoietic cells, mice were treated with a US Food and Drug Administration approved β3 receptor agonist, mirabegron. As expected, mirabegron treatment increased the Cdc42 activity in HSCs and increased Ly6C^low production and concentration in the brain. Most importantly mirabegron treatment reduced functional neurological deficits, perihaematomal oedema, and overall brain oedema after ICH.

This article demonstrates that brain injury leads to a cascade of mechanisms modulated by β3-adrenergic innervation in which an NCM population provides protective effects to the brain. Lastly, the authors tested a potential targeted therapy upregulating the pathway and demonstrated improvement in brain injury outcomes.

Brain injuries have unique mechanisms that differ from peripheral organ injury. In normal conditions, the brain is sheltered within the blood brain barrier (BBB); endothelial cells and the microvasculature tightly regulate the exchange of molecules, ions, and cells from the blood to the brain.² When the brain is injured, in particular in traumatic brain injury (TBI), there is a combination of mechanical disruption and endothelial dysfunction leading to BBB permeability. Disruption of the BBB leads to the circulation of brain-derived damage associated molecular patterns (DAMPs) in the peripheral circulation.³ At the same time, the injured brain is exposed to the peripheral circulation, due to BBB disruption. The complex interplay and cross-talk between the injured brain and the distant organs is just beginning to be investigated.

Shi et al¹ add to the body of literature evaluating the connection between brain injury and the immune system. Given the relatively broad potential aetiologies of ICH (e.g. trauma, aneurysm rupture, tumour, coagulopathy), this article is widely applicable and should stimulate future questions in understanding brain injury. Severe TBI has been associated with a systemic inflammatory response syndrome with downstream effects that can lead to multi-organ dysfunction (MOD). The systemic response provides notable clinical evidence for the interactions between the brain and periphery. In 2021, Yang et al evaluated the role of the Ly6c^low NCM in the mechanisms of pulmonary oedema following TBI.⁴ Their group demonstrated that there is a significant increase in Ly6c^low NCM in the lungs of mice after TBI. Upon depletion of NCMs, there was a decrease in pulmonary oedema suggesting that NCMs contribute to post-TBI lung injury. Taken together, these articles show that NCMs are stimulated in the bone marrow following TBI. Subsequently, their response plays a role in both local brain inflammation, as well as distant organ injury. Interestingly, while the Ly6c^low NCM migration appears to improve brain injury,¹ the increase of Ly6c^low in the lungs was associated with worse outcomes. Given the interconnected nature of the immune system, these findings raise many more questions than answers. Among the many are: what the NCM response is in other organs, what downstream cell type do they effect, and how do the NCMs migrate to the distant organs?

In understanding the mechanisms and pathways driving the brain and peripheral cross-talk, we may begin to not only investigate therapies and diagnostics in brain injury, but also target the associated MOD. Currently, the treatment for brain injury is largely supportive, with no interventions that target the underlying mechanisms. These mechanisms provide promising avenues for future research and the potential for advancing the clinical management of TBI and other brain injuries.

An additional future application may be in the field of transplantation. Solid organ allografts from donation after brain death, the leading source of donor organs, have been noted to have inferior graft survival compared to those from living donors.⁵ Given the systemic nature of brain injury and brain death, it is likely that the organs similarly undergo immune and inflammatory responses, potentially predisposing the allograft to dysfunction post-transplantation.

 Thus, a better understanding of what happens at the cellular and molecular levels following brain injury may have wide-reaching clinical benefits. In addition to the potential to improve outcomes for patients with brain injury, the effects on post-transplantation organ function highlight the central role of basic and translational investigation in the development of novel therapies. This sentiment was probably best captured by the Noble Laureate Francis Crick (1916-2004) when he wrote “Almost all aspects of life are engineered at the molecular level, and without understanding molecules we can only have a very sketchy understanding of life itself.” What Mad Pursuit (1988).

Maemoto R, Noda H, Ichida K, Miyakura Y, Kakizawa N, Machida E et al.

Ann Surg 2023; 277: 727-733.

Lavage with povidone iodine before skin closure for 1 min was compared to saline lavage in this study that included 941 procedures. The rate of surgical site infection was similar: 7.6 per cent with iodine and 5.1 per cent with saline, P=0.154.

Comment: the fact that the wound is flushed may be more important than what with.

D’Angelica MI, Ellis RJ, Liu JB, Brajcich BC, Gonen M, Thompson VM et al.

JAMA 2023; 329: 1579-1588.

The trial was stopped after interim analysis of 778 procedures. The combination of piperacillin and tazobactam reduced the risk of surgical site infection at 30 days: 19.8 versus 32.8 per cent, P<0.001. It also reduced the rate of relevant postoperative pancreatic fistula: 12.7 versus 19 per cent, P=0.03.

Comment: Promising new combination for open pancreatic surgery.

Piatkowski AA, Wederfoort JLM, Hommes JE, Schop SSJ, Krastev TK, van Kuijk SMJ et al, for the Breast Reconstruction With External Preexpansion & Autologous Fat Transfer vs Standard Therapy (BREAST) Trial Investigators.

JAMA Surg 2023; 158: 456-464.

There was no evidence that fat transfer was unsafe in this study that included 193 women. Quality of life was improved in all five domains in women who had the fat transfer procedure in the 132 women who completed the study (all domains P<0.05). There were no differences in complications or oncological outcomes.

Comment: Less invasive than breast reconstruction.

Etoh T, Ohyama T, Sakaramoto S, Tsuji T, Lee S-W. Yoshida K et al,  for the Japanese Laparoscopic Surgery Study Group (JLSSG).

JAMA Surg 2023; 158: 445-454.

After five years in this study that included 502 patients, there was no difference between the two procedures in relapse-free survival: 73.9 per cent open versus 75.5 per cent laparoscopic resection, P=0.03 for non inferiority. Nor were there differences in postoperative complications, or overall survival.

Comment: No difference in outcomes, so choice of procedure should be according to patient choice, but perhaps also cost in publicly funded healthcare systems.

Gerard J-P, Barbet N, Schiappa R, Magne N, Martel I, Mineur L et al, on behalf of the ICONE group.

Lancet Gastrohepatol 2023; 8: 356-367.

This study explored whether a radiotherapy booster was beneficial in 148 patients with a complete response to neoadjuvant chemoradiotherapy. Three-year preservation of the rectum was more likely after contact brachytherapy (81 per cent) versus 59 per cent for booster external beam radiotherapy, P=0.0026. The effect was greatest for tumours <3cm in diameter.

Comment: Management of rectal tumours with the aim to avoid ablative surgery is evolving.

Verrastro O, Panunzi S, Castagneto-Gissey L, De Gaetano A, Lembo E, Capristo E et al.

Lancet 2023; 401: 1786-1797.

A total of 288 patients were randomly allocated to best medical therapy or one of two bariatric procedures. Stereohepatitis resolved in 70  per cent of patients who had either Roux-en-Y gastric bypass or sleeve gastrectomy compared to 19 per cent in the best medical treatment group; P<0.0001.

Comment: This study shows convincing evidence that non-alcoholic fatty liver can be reversed by bariatric surgery. Is that alone a reasonable indication?

Gasior SA, O’Donnell JPM, Davey M, Clarke J, Jalali A, Ryan E et al.

Eur J Vasc Endovasc Surg 2023; 65: 690-699.

Over 14000 people were included  in this analysis. It concluded modern best medical therapy had similar reductions in stroke and death rates to carotid endarterectomy. It was not possible to define any subgroups that might benefit from vascular intervention.

Comment: complex and detailed study undermining the previously agreed role of vascular intervention.

Bekken JA, Vroegindeweij D, Vos JA, de Vries J-PPM, Lardenoije JWHP, Petri B-J et al.

Eur J Vasc Endovasc Surg 2023; 65: 359-368.

Freedom from restenosis after two years was 84.7 per cent after bare stents versus 89.1 per cent with covered stents (P=0.4) in this study that included 174 limbs. Technical success and complication rates were similar.

Comment: no advantage for the covered stent.

Gunnarson T, Bergman S, Parsson H, Gottsater A, Lindgren H.

Eur J Vasc Endovasc Surg 2023; 65: 513-519.

In this study that included 100 patients, after 30 months, insertion of a stent improved role physical quality of life (QoL) scores, but not overall QoL, compared to best medical therapy. By 60 months QoL was similar in the two groups.

Comment: endovascular intervention for SFA disease is not a good long term solution.

Serradilla-Martín M, Paterna-López S, Palomares-Cano A, Cantalejo-Díaz M, Abadía-Forcén T, Gutiérrez-Díez ML, et al.

BJS Open 2023; 7: zrad028.

Use of the patch reduced the rate of clinically relevant postoperative pancreatic fistula by 90 per cent; odds ratio 0.1, 95 per cent confidence interval 0.01 to 0.89, P=0.039, in this study that included 64 procedures.

Comment: amazing result, but relatively small series.

Pfister M, Probst P, Muller PC, Antony P, Klotz R, Kalkum E et al. 

BJS Open 2023; 7: zrad007.

This study included 984 patients from six RCTs. Minimally invasive surgery reduced blood loss, surgical site infection (odds ratio 0.4, 95 per cent confidence interval 0.1 to 0.96, P=0.04) and hospital stay by 1.3 days (-2 to -0.5, P=0.001). On average the surgery took 75 minutes longer, P<0.001.

Comment: this is a common result for laparoscopic versus open surgery studies, but a definitive comparison includes late outcomes in cancer cases, and costs (see also Sattari et al).

Sattari SA, Sattari AR, Makary MA, Hu C, He J.

Ann Surg 2023; 277: 742-755.

Four RCTs including 818 procedures were studied. The laparoscopic procedure took longer, but was associated with less blood loss, fewer surgical site infections and reduced length of hospital stay: mean 2.5 days, P=0.06.

Comment: this is a common result for laparoscopic versus open surgery studies, but a definitive comparison includes late outcomes in cancer cases, and costs (see also Pfister et al).

Welcome to the @BJSAcademy social media review for June 2023, where we highlight some of the most interesting and relevant posts from BJS community accounts. In fact, we have chosen some tweets with 15 or more likes.

Whether you are a trainee, a consultant, or a researcher, we hope you will find something useful and inspiring in this digest. Please feel free to share your feedback and suggestions with us on Twitter, Facebook, or Instagram. Thank you for your support and engagement!

On June 3rd, @BJSurgery tweeted a retrospective study comparing endoscopic retrograde appendicitis therapy with antibiotics for uncomplicated appendicitis:

The manuscript can be accessed here

Mechanical bowel preparation and antibiotics is a never-ending story. On June 5th, @BJSOpen shared the link to a metanalysis on this topic. It is worth reading:

The manuscript can be accessed here.

Breaking news! On June 6th @BJSAcademy announced the recipient of inaugural BJS Society Award: Prof. Henrik Kehlet:

@BJSurgery shared an open access paper reporting the results of the international Watch and Wait registry on June 9th. A must-read paper for colorectal surgeons:

The paper can be accessed here.

No doubt fluorescence-guided surgery is a hot topic. You can read an outstanding review by @BJSurgery editor Paul Sutton that was tweeted by @BJSOpen on June 10th:

The paper can be accessed here.

On June 11th, @BJSurgery shared an open access paper on diagnosis and treatment for gastro-oesophageal cancer in England and Wales. What’s the most important finding? Little improvements in early diagnosis:

The paper can be accessed here.

The #openaccess leading article titled “Bi-directional chemotherapy for peritoneal metastases”  was tweeted by @BjSurgery on June 14th:

The paper can be accessed here.

The BJS Society Award Ceremony was held at the Olympic Museum in Lausanne on June 16th. On that same date, @BJSAcademy tweeted “A surgical life by Henrik Kehlet”. We highly recommend you read it if you want to know more about Prof. Kehlet and how surgeons can translate knowledge into impact:

The article can be accessed here:

Simultaneously, @BJSOpen shared a tweet congratulating Prof. Kehlet, the BJS Society Award winner:

@BJSAcademy also tweeted pictures of the ceremony on June 17th. In fact, it was truly a fantastic event:

Little is known about the impact of cognitive biases on surgical outcomes. On June 20th, @BJSurgery shared a metanalysis of studies that investigated cognitive bias in surgery:

The paper can be accessed here.

On June 23rd, @BJSurgery announced the three successful applicants for @BJSurgery and @BJSOpen editor assistant positions. Congratulations @mikeboland86, @PhilipMueller_1 and @TejedorPat:

A very much liked @BJSurgery tweet shared an article by @swexner’s group reporting a propensity score-matched outcomes study for robotic and laparoscopic colectomy from a national cancer database on June 27th:

The article can be accessed here.

Last but not least, @BJSOpen took advantage of its blue tick and tweeted the abstract of the paper titled “Global cost of postoperative ileus following abdominal surgery: meta-analysis” on June 28th. It has received 33 likes by July 2nd:

The article can be accessed here.

Based on: Lebrun LJ, Lenaerts K, Kiers D, Pais de Barros JP, Le Guern N, Plesnik J, et al. Enteroendocrine L Cells Sense LPS after Gut Barrier Injury to Enhance GLP-1 Secretion. Cell Rep. 2017;21(5):1160-8.

https://doi.org/10.58974/bjss/azbc021

One of the most vexing issues in the field of inflammation research pertains to how the very bacteria and cells in the intestine that are required for host survival can also induce life-threatening inflammation. In its mildest form, inflammation in the gut may induce only brief discomfort or food intolerance, whereas in the extreme, gut inflammation can manifest as Crohn’s disease or ulcerative colitis, with life threatening implications. The precise factors that either accelerate or stop the development of inflammation in the intestine remain incompletely understood. The work of Lebrun et al now adds an important piece to this puzzle by describing a critical and previously unrecognized role for the gut-derived hormone glucagon-like-peptide 1 (GLP-1) in the regulation of intestinal inflammation.

Enteroendocrine cells (EECs) are specialized epithelial cells that are responsible for the release of a variety of gut hormones. Chief amongst the various hormones that are secreted from the EECs is GLP-1, a peptide whose actions result in the regulation of circulating glucose, the control of appetite, and the motivation for food intake. Agonists of the GLP-1 receptor have been developed to treat type 2 diabetes, and recent studies suggest that such agonists may also have important effects in the control of obesity^{1, 2}. In foundational studies leading up to the current work, other authors have focused on the fact that enteric bacteria produce lipopolysaccharide (LPS) that can influence gut hormone release^{3, 4}. LPS mainly acts through the activation of toll-like receptor 4 (TLR4), a membrane bound receptor that serves as a convergence point for both infectious and non-infectious stimuli, triggering a proinflammatory response⁵. Under normal physiological conditions, several mechanisms restrict LPS signaling within the gut lumen; however, in inflammatory disease states, particularly when intestinal barrier integrity and function may be compromised, LPS can enter the circulation, where it can activate TLR4 on inflammatory cells and trigger a systemic inflammatory response.

Lebrun et al. set out to determine whether enteroendocrine cells (EECs) could sense circulating LPS and thus release GLP-1 in order to modulate the pro-inflammatory response⁶. Starting with a murine ileum explant model, the authors showed that intraluminal LPS could stimulate GLP-1 secretion and that GLP-1 secretion was rapidly increased after direct LPS stimulation of an EEC cell line (STC-1 cells). Plasma levels of pro- and anti-inflammatory cytokines were increased in wild-type (WT) but not in TLR4-deficient (Tlr4^−/−) mice, while GLP-1 secretion could be abolished when STC-1 cells were exposed to LPS in the presence of a TLR4 antagonist (TAK-242). These findings point to the critical role of TLR4 in coupling LPS to GLP-1 secretion.

Next, the authors used animal models to investigate the effect of LPS on GLP-1 secretion in the setting of compromised gut barrier function. They found that LPS administration either intravenously or intraperitoneally induced GLP-1 secretion, while no effects were observed when LPS was administered orally to mice with an intact intestinal barrier. In contrast, in models of compromised gut barrier function (DSS-induced colitis and mesenteric ischaemia/reperfusion injury models), oral administration of LPS increased GLP-1 secretion. This increase could be blunted by treatment with an antibiotic that binds to LPS (polymyxin B) or by a TLR4 antagonist (TAK-242). The authors also found that IL-6 was linked to the stimulation of GLP-1 secretion, as injection of LPS into IL-6 deficient mice led to an attenuated increase in GLP-1 release. Finally, the authors performed experiments on human subjects to evaluate the impact of LPS injection on plasma GLP-1 levels. Three hours after LPS injection, there was an observed increase in GLP-1 levels that was not seen after saline injection. The authors point out that other studies have shown heightened levels of circulating GLP-1 in critically ill patients⁷, who would presumably have some degree of impaired intestinal barrier function. In summary, these studies reveal that enteroendocrine cells and GLP-1 have roles that extend well beyond their known metabolic functions, suggesting they may be crucial sensors of gut injury.

There are several important implications of the current work. First, and most obviously, GLP-1 may emerge as a promising candidate biomarker for the early detection of gut injury in humans, while also representing a novel therapeutic target for the control of inflammation in the gut. Second, the canonical TLR4 pathway is now shown to be a crucial driver of the signals linking LPS to the stimulation of GLP-1 secretion. The ensuing negative feedback loop may involve not only EECs but also Paneth cells and intestinal intraepithelial lymphocytes, as these cells have been reported to express the receptor for GLP-1 (namely GLP-1R), and loss of GLP-1R increases the severity of DSS-induced intestinal injury^{8, 9}. These results are also consistent with previous studies showing that GLP-1 analogues improve gut permeability and protect the gut against oxidative damage^{10, 11}, strengthening the current work.

While the studies by Lebrun et al have exciting implications for the treatment of gut injury and critical illness, the precise cell types (i.e. immune vs. epithelial cells) that are responsible for recognizing LPS in order to induce the release of GLP-1 from EECs remain unknown. Moreover, the various steps by which GLP-1 can act to limit inflammation still remain unresolved. That said, the current work greatly advances our understanding of how bacterial signalling in the gut can both induce and also curtail intestinal inflammation, and reveals an exciting role for the gut hormone GLP-1 as a potential therapeutic target in the regulation of inflammatory diseases of the intestine.

This is a selection of tweets posted by @BJSurgery @BJSOpen and @BJSAcademy between May 1^st and May 30^th 2023. We hope you enjoy them and would like to read your comments.

On May 1st, @BJSAcademy tweeted an important announcement: the new BJS Institute online #postgrad programme – Surgical Writing and Evidence-Based Practice.

You can find further information here.

On the same day, @BJSAcademy posted the article of the month for April: Basic Introduction to Artificial Intelligence by @tejedorpat. It is part of the @BJSAcademy #AI series:

The article can be read here.

One day later, May 2nd, @BjsOpen tweeted: “#RCT from China with n=96 shows that single ivof 1.5mg/kg lignocaine 10min b.f. tourniquet inflation in arthroscopic surgery inhibits tourniquet hypertension by TNF-α release & has beneficial effects on postop pain and recovery!”

The paper can be read here.

Coinciding with #EuroHernia2023, @BjsOpen quoted a tweet: “Our editor assistant, hernia enthusiast and collagen nerd @DrHenriksen talking about state of the art #hernia surgery at @BarcelonaEhs!!! #SoMe4Surgery @eurohernias @BJSAcademy @young_bjs:

The interview with Donald E. Low was tweeted by @BJSAcademy on May 5th: “Have the right partner at home and have the right partners at work.”

The interview can be read here.

On the same day, @BJSurgery shared a free access paper: Early-onset sporadic colorectal cancer: key question of early diagnosis and screening strategies:

The paper can be read here.

Two days later, May 7th, @BJSurgery tweeted a very interesting paper on machine learning-based prediction models in the perioperative setting:

The paper can be read here.

On May 9th, @BJSAcacemy announced that the second article in the AI series was available. The authors are @irene_spiridon and @DocSeeliger and the paper is about the optimisation of surgical pathology and the potential role of AI:

The paper can be read here.

@BjsOpen tweeted a must-read review about hereditary colorectal, gastric and pancreatic cancer on May 11th:

The manuscript can be read here.

On May 13th, an open access paper titled “Timing of symptomatic venous thromboembolism after surgery: meta-analysis” was shared by @BJSurgery:

The paper can be read here.

Four days later, on May 17th, @BJSurgery shared two important papers:

A #RCT investigating prophylactic onlay mesh placement techniques for optimal abdominal wall closure in an ex vivo biomechanical model:

The paper can be read here.

An #OpenAccess paper titled “Surgical Outcome Risk Tool to predict 30-day postop mortality in a mixed surgical population in Swedish tertiary hospitals”:

The paper can be read here.

On the same day, @BjsOpen shared a paper reviewing the current state of fluorescence-guided surgery by @BJSurgery editor @paulo_sutt et al.

The paper can be read here.

On May 18th, @BjsOpen added more fuel to the “volume debate” in colorectalsurgery with these questions: What’s the correlation of surgical specialization and surgeon resection volume on short-term outcome after emergent colon cancer resections? Differences between colorectal, general and acute care surgeons? 

The paper can be seen here.

@BJSurgery congratulated Candice Downey on winning the BJS Prize at the ASGBI Surgical Congress in Harrogate, UK! #ASGBI2023 on May 19th:

An interesting poll was tweeted by @BjsOpen on May 21st: Leftsided colorectal leading to bowel obstruction -> What type of stoma you prefer as to surgery?

The results can be seen here:

On May 22nd, @BJSurgery shared another “Free to access” paper in the BJS May issue: Practice of changing gloves and its effect on surgical-site infections.

The paper can be read here.

A tweet to thank all the speakers and participants who contributed to the @BJSAcademy workshop – “how to referee a paper” was posted on May 27th:

The last tweet of the month was posted on May 30th by @BJSurgery and shared the manuscript titled: “Clinical outcomes following mechanochemical ablation of superficial venous incompetence compared with endothermal ablation”:

The paper can be read here.

Bradbury AW, Moakes CA, Popplewell M, Meecham L, Bate GR, Kelly L et al, on behalf of the BASIL-2 Investigators.

Lancet 2023; 401: 1798-1809.

Some 345 patients with critical leg ischaemia were treated and followed for two years. The outcome of major amputation or death occurred in  63 per cent of the surgery first group compared to 53 per cent after endovascular treatment first, P=0 .037. This outcome was mainly due to the high rate of death in the two years after surgery (53 versus 45 per cent).

Comment: This was an unexpected result after the converse outcome in the recent BestCLI trial. It requires further explanation. Were the patients with critical leg ischaemia different in the UK and USA?

Lim AJM, Abduraheem HM, Hitchman LH, Lathan R, Bharadhwaj R, Sidapra MM et al.

Br J Surg 2023; 110: 562-567.  

Four randomized trials including 654 patients were analyzed. The rate of occlusions was lower after mechanical ablation: risk ratio of 0.85, 95 per cent confidence interval 0.78 to 0.91, P<0.000. There was no difference in pain during the procedure or clinical outcomes.

Comment: The role of mechanical ablation remains unproven. It doesn’t seem as effective as endothermal ablation, although the occlusion rate as an endpoint may not be ideal.

Mei W-J, Wang X-Z, Li Y-F, Sun Y-M, Yang C-K, Lin J-Z et al.

Ann Surg 2023; 277: 557-564.

In this study that included 589 procedures, neoadjuvant chemotherapy with radiotherapy had similar effect on complete pathological response and downstaging. Radiotherapy increase the risk of needing an ileostomy: 63.6 versus 52.2 per cent, P= 0.008.

Comment: The late outcomes of this trial will reveal whether additional radiotherapy is worthwhile.

Bouzat P, Charbit J, Abback P-S, Huet-Garrigue D, Delhaye N, Leone M et al, for the PROCOAG Study Group.

JAMA 2023; 329: 1367-1375.

In this study of 327 injured patients, use of the prothrombin complex did not reduce the need for blood transfusion within the first 24 hours: 12 versus 11 units, P=0.72. It did increase the risk of thrombotic events by around 11% , P=0.03

Comment: Disappointing results.

Early Breast Cancer Trialists’ Collaborative Group (EBCTCG).

Lancet 2023; 491: 1277-1292.

This huge analysis of women treated for breast cancer showed that the combination of anthracycline and taxane regimens was most effective at reducing breast cancer recurrence. The higher dose regimens produced the greatest effects.

Comment: I really admire this sort of analysis which provides very important information that influences treatment strategies.

The following tweets were posted between April 1st and April 29th, 2023. They contain useful information and insights about various topics related to surgery. You can browse through them and find the ones that are most relevant to your interests and needs.

Coping with anastomotic leaks, harder when older? Tweeted by @BJSurgery on April 1st:

The paper can be read here.

Lies, damn lies, and statistics. On April 3rd @BJSurgery shared a paper on probability, P values, and statistical significance: instructions for use by surgeons:

The paper can be read here.

On April 4th, @BJSurgery shared a Young BJS paper: hiatal hernia:

The paper can be read here.

What did you learn in the operating room? Soft skills @BJSAcademy:

The post can be read here.

The instrumentalist: Weitlaner retractor. Tweeted by @BJSurgery on April 17th:

The paper can be seen here.

It may not sound sophisticated, but it is extremely important. On April 10th, @BJSurgery shared the NINJA multicentre randomized clinical trial investigating the effectiveness of nail bed repair in children with or without replacing the fingernail:

The paper can be read here.

On April 11th, a randomized trial on the use of haemostatic patches to prevent pancreatic fistula after pancreatic resections was shared by @BJSOpen:

The paper can be read here.

@BJSOpen ran a Twitter poll on the use of ursodeoxycholic acid to treat gallstone disease on April 16th. Of the 269 participants, 52.8% voted that they do not use it:

The paper can be read here.

On the same day, @BJSurgery tweeted an open access paper on double faecal immunochemical testing in patients with symptoms suspicious of colorectal cancer:

The manuscript can be read here.

On April 17th, @BJSAcademy announced the launch of the AI series on Twitter. These are the topics:

• Basic Introduction to AI
• Surgical Pathology and AI
• Role of AI in clinical surgery
• AI in Radiology
• Big Data
• The Future

An interesting #systematicreview and meta-analysis of machine learning models in kidney TPL found they could improve prediction of graft survival. An overall model including 29 models showed sens & spec of 0.81 and AUC of 0.82. It was tweeted by @BJSOpen:

The manuscript can be read here.

On April 25^th, @BJSAcademy tweeted the first of a series on AI: “Basic Introduction to Artificial Intelligence” The aim is to describe how it works and its importance to healthcare:

The post can be read here.

@BJSAcademy tweeted #BJSBookshelf: Top Knife: The Art and Craft of Trauma Surgery, on April 28th. We recommend you read the review by Teresa Perra & Alberto Porcu:

The post can be read here.

On April 29^th, @BJSOpen tweeted a #systematicreview of training surgeons to optimize communication and symptom management in patients with life-limiting conditions:

The paper can be read here.

On the same date, @BJSurgery shared the international guidelines on management of general surgical emergencies in the pregnant or breastfeeding woman:

The paper can be read here.