The pursuit of appropriate, biocompatible materials is one of the primary challenges in translational bioprinting. The requirement to refine a biomaterial into a bioink places additional demands on the criteria for candidate biomaterials. The material must enable extrusion as a liquid bioink and yet be capable of maintaining its shape in the post-printing phase to yield viable tissues, organs and biological materials. Plant-derived biomaterials show great promise in harnessing both the natural strength of plant microarchitecture combined with their natural biological roles as supporters of cell growth. The aim of this review article is to outline the most widely used biomaterials derived from land plants and marine algae: nanocellulose, pectin, starch, alginate, agarose, fucoidan, and carrageenan, with an in-depth focus on nanocellulose and alginate. The properties that render these materials as promising bioinks for three dimensional bioprinting is herein discussed alongside their potential in 3D bioprinting for tissue engineering, drug delivery, wound healing, and implantable medical devices.

Background Ileus is common after elective colorectal surgery, and is associated with increased adverse events and prolonged hospital stay. The aim was to assess the role of non‐steroidal anti‐inflammatory drugs (NSAIDs) for reducing ileus after surgery. Methods A prospective multicentre cohort study was delivered by an international, student‐ and trainee‐led collaborative group. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The primary outcome was time to gastrointestinal recovery, measured using a composite measure of bowel function and tolerance to oral intake. The impact of NSAIDs was explored using Cox regression analyses, including the results of a centre‐specific survey of compliance to enhanced recovery principles. Secondary safety outcomes included anastomotic leak rate and acute kidney injury. Results A total of 4164 patients were included, with a median age of 68 (i.q.r. 57–75) years (54·9 per cent men). Some 1153 (27·7 per cent) received NSAIDs on postoperative days 1–3, of whom 1061 (92·0 per cent) received non‐selective cyclo‐oxygenase inhibitors. After adjustment for baseline differences, the mean time to gastrointestinal recovery did not differ significantly between patients who received NSAIDs and those who did not (4·6 versus 4·8 days; hazard ratio 1·04, 95 per cent c.i. 0·96 to 1·12; P = 0·360). There were no significant differences in anastomotic leak rate (5·4 versus 4·6 per cent; P = 0·349) or acute kidney injury (14·3 versus 13·8 per cent; P = 0·666) between the groups. Significantly fewer patients receiving NSAIDs required strong opioid analgesia (35·3 versus 56·7 per cent; P < 0·001). Conclusion NSAIDs did not reduce the time for gastrointestinal recovery after colorectal surgery, but they were safe and associated with reduced postoperative opioid requirement.

Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien–Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P &lt; 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P &lt; 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk.

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Background Postoperative acute kidney injury (AKI) is a common complication of major gastrointestinal surgery with an impact on short- and long-term survival. No validated system for risk stratification exists for this patient group. This study aimed to validate externally a prognostic model for AKI after major gastrointestinal surgery in two multicentre cohort studies. Methods The Outcomes After Kidney injury in Surgery (OAKS) prognostic model was developed to predict risk of AKI in the 7 days after surgery using six routine datapoints (age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker). Validation was performed within two independent cohorts: a prospective multicentre, international study (‘IMAGINE’) of patients undergoing elective colorectal surgery (2018); and a retrospective regional cohort study (‘Tayside’) in major abdominal surgery (2011–2015). Multivariable logistic regression was used to predict risk of AKI, with multiple imputation used to account for data missing at random. Prognostic accuracy was assessed for patients at high risk (greater than 20 per cent) of postoperative AKI. Results In the validation cohorts, 12.9 per cent of patients (661 of 5106) in IMAGINE and 14.7 per cent (106 of 719 patients) in Tayside developed 7-day postoperative AKI. Using the OAKS model, 558 patients (9.6 per cent) were classified as high risk. Less than 10 per cent of patients classified as low-risk developed AKI in either cohort (negative predictive value greater than 0.9). Upon external validation, the OAKS model retained an area under the receiver operating characteristic (AUC) curve of range 0.655–0.681 (Tayside 95 per cent c.i. 0.596 to 0.714; IMAGINE 95 per cent c.i. 0.659 to 0.703), sensitivity values range 0.323–0.352 (IMAGINE 95 per cent c.i. 0.281 to 0.368; Tayside 95 per cent c.i. 0.253 to 0.461), and specificity range 0.881–0.890 (Tayside 95 per cent c.i. 0.853 to 0.905; IMAGINE 95 per cent c.i. 0.881 to 0.899). Conclusion The OAKS prognostic model can identify patients who are not at high risk of postoperative AKI after gastrointestinal surgery with high specificity. Presented to Association of Surgeons in Training (ASiT) International Conference 2018 (Edinburgh, UK), European Society of Coloproctology (ESCP) International Conference 2018 (Nice, France), SARS (Society of Academic and Research Surgery) 2020 (Virtual, UK).

Aim Non-melanoma skin cancers (NMSC) are the most common malignancies worldwide, with basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) constituting an ever-growing clinical burden within Plastic & Reconstructive Surgery. In this 3-cycle Quality Improvement (QI) initiative we sought to evaluate and improve our unit’s compliance with British Association of Dermatology (BAD) guidance on excision margins for NMSCs. Method Following results from two Plan-Do-Study-Act (PDSA) cycles, a third retrospective review of clinic letters, operative notes and histopathology reports was undertaken to identify NMSCs that were excised during May 2021 and assess compliance with recommended excision margins according to risk stratification. Results The dissemination of cycle 1 findings at departmental meetings, as well as the implementation of guideline posters and operative note templates conferred a significant improvement in both clinical documentation (12% to 100%) and local compliance with excision margin guidelines for BCCs (53% to 71%) and SCCs (50% to 79%). Following the adoption of new BAD guidelines on SSC margins in early 2021, a third cycle comprising 42 lesions demonstrated a sustained improvement in clinical documentation (100%) after a 7-month period and similar guideline compliance rates for both BCC (67%) and SCC (78%). Conclusions Adequate excision margins in cutaneous malignant pathology are vital to ensure complete removal, thus minimising the risk of recurrence. Although improvement across the PDSA cycles has been sustained despite the introduction of new SCC margin guidelines, we aim to introduce further interventions such as a knowledge and practice survey to continue improving excision margin compliance.

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Aim To investigate medical students’ understanding of skills needed as surgeons and how prepared they feel to pursue surgical careers, and to identify methods to support and prepare medical students who want to pursue surgical careers. Method A student-led National Surgical Conference (Cardiff, 2018) ran a consensus and debate session entitled ‘Are students adequately prepared for a career in surgery at medical school?’, including a questionnaire addressing elements of medical school curriculums relevant to surgery and the importance of developing technical skills and non-technical skills (NTS). Results 60 delegates completed the questionnaire: Year1-3 (n = 38), Year4-6 (n = 15), intercalating (n = 4), foundation doctors (n = 3). Delegates most frequently stated specific surgical skills (20.1%), broader surgical skills (20.1%) and interpersonal skills (17.2%) as the most important skills to be a surgeon. 75% rated technical skills and NTS as equally important, 25% rated technical skills as more important. 12.5% felt unconfident in their NTS to be an efficient surgical team-member, 37.5% felt between confident and unconfident, and 50% were confident. 26.3% felt unprepared to pursue surgical careers following medical school, 70.2% felt between prepared and unprepared, and 3.5% felt prepared. More practical surgical skills sessions (35%), career pathway sessions (15%), surgically relevant teaching (16%) and theatre or surgical placements (19%) were the most frequently wanted improvements. Conclusions Prospective surgeons highly valued developing surgical skills and overall do not feel prepared to pursue surgery. Medical students would benefit from education on the surgical career pathway and the importance of the non-practical components of surgery, including patient safety and NTS.