Research Appraisals
Evidence-based critical appraisals of the latest medical research, systematically evaluated using Oxford CEBM methodology.
Showing 6 appraisals
Journal of robotic surgery
Robot-assisted versus open kidney transplantation: an umbrella review of systematic reviews and meta-analyses
Robot-assisted kidney transplantation (RAKT) has emerged as a minimally invasive alternative to open kidney transplantation (OKT). However, the comparative benefits and limitations of both approaches remain unclear. To compare the outcomes of RAKT and OKT through an umbrella review of published systematic reviews and meta-analyses. This umbrella review was written following PRISMA guidelines. Only meta-analysis and systematic review were included. Many outcomes were studied such as warm (WIT) and cold ischemia times (CIT), rewarming time, total ischemia time, blood loss, blood transfusion, delayed graft function, surgical site infections (SSI), hospital stay, graft rejection, graft failure, all-cause mortality, operation time, incision length, hospital readmission, vascular and ureteral anastomosis time, and other complications. We assessed methodological quality via the AMSTAR-2 tool. Consistency and strength of evidence were also evaluated. 6 studies were included: four meta-analyses and two systematic reviews. Studies were of low to moderate quality. Robotic kidney transplant surgery yields better outcomes in terms of blood loss (MDs ranging from - 16 to - 55 mL across studies), post-operative pain, incision length, SSI and ureteral leak. On the other hand, CIT, rewarming time, total ischemia time, operative time and ileus rate were favored in open surgery. Same rejection rates, graft failure, mortality and hospital readmission rate were found between both techniques. RAKT appears to improve several perioperative outcomes while maintaining comparable graft and patient survival outcomes to OKT. However, the available evidence remains limited by the low-to-moderate quality of existing reviews, highlighting the need for high-quality prospective studies.
27 July 2026
Read appraisal →Health care management science
Improving hard-to-place kidney allocation: A machine learning approach to center ranking
Kidney transplantation is the preferred treatment for end-stage renal disease, yet donor scarcity and inefficiencies in allocation systems create major bottlenecks, resulting in prolonged wait times and alarming mortality rates. Despite the severe shortage of donor kidneys, timely and effective interventions to prevent non-utilization of life-saving organs remain limited. Expedited out-of-sequence placement of hard-to-place kidneys to centers with a high likelihood of acceptance has been recommended in the literature as a strategy to improve placement success. However, in practice, this process remains nonstandardized and relies heavily on the subjective judgment of decision-makers. We propose a data-driven, machine learning-based ranking policy for out-of-sequence allocation of hard-to-place kidneys that prioritizes transplant centers using predicted center-level acceptance probabilities. Using national deceased-donor and kidney-offer data, we construct a unique offer-level dataset with donor- and center-specific features. We also employ machine learning interpretability tools to provide insight into the factors influencing kidney allocation decisions. Our analysis demonstrates that the proposed policy can reduce the average number of centers considered before placement by fourfold for all kidneys and tenfold for the subset of hard-to-place kidneys. These results highlight the potential of the proposed framework to improve the efficiency of expedited placement and support more timely utilization of hard-to-place kidneys.
17 July 2026
Read appraisal →BMJ open
Impact of climatic variables on postoperative outcomes in various surgical disciplines: a systematic review.
OBJECTIVES: The impact of climate change on health is well recognised, yet its influence on postoperative complications remains underexplored. This systematic review examines how climatic factors-particularly temperature, humidity and seasonal variations-affect surgical outcomes. DESIGN: Systematic review with narrative synthesis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. DATA SOURCES: A comprehensive search of PubMed, Web of Science and the Cochrane Library from June 2015 to June 2025 was conducted. An additional supplementary PubMed search was performed to identify further relevant studies. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Included were studies published in English or German that examined associations between climatic factors, including temperature, humidity, precipitation or seasonality and postoperative outcomes in surgical patients. Studies without a surgical or climatic focus, animal studies, reviews and commentaries were excluded. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently screened studies and extracted data using predefined criteria. Risk of bias was assessed using the Newcastle-Ottawa Scale. Due to methodological heterogeneity, findings were synthesised narratively. RESULTS: Fifteen studies were included. High ambient temperatures were frequently associated with increased risks of surgical site infections (SSIs). Some large studies reported that even a one-degree rise significantly elevated infection rates. Humidity was also linked to higher infection rates, with evidence suggesting an independent effect in some cases. Seasonal changes influenced complication rates across regions and surgical disciplines, with infection and pneumonia peaks in summer or winter months. A few studies reported increased risks during heavy rainfall or institutional transitions such as the 'July effect'. CONCLUSION: Overall, elevated temperature and humidity appear to be associated with increased postoperative risks, especially SSIs. Seasonal patterns may further influence outcomes depending on geography and procedure type. While the available evidence supports a link between climate and surgical complications, methodological differences and limited adjustment for confounders highlight the need for more rigorous studies.
5 July 2026
Read appraisal →Journal of gastrointestinal cancer
Durable Survival Outcomes After Liver Transplantation for Colorectal Liver Metastases: A Systematic Review and Single-arm Meta-analysis of Prospective Clinical Trials
BACKGROUND: Liver transplantation (LT) has emerged as a potential treatment option for selected patients with colorectal liver metastases (CRLM), but existing meta-analyses are limited by heterogeneous populations and mixed treatment modalities. METHODS: A systematic review and single-arm meta-analysis were conducted in accordance with PRISMA guidelines. Studies reporting outcomes following LT for CRLM were included. Primary outcomes were overall survival (OS) and progression-free survival (PFS) at predefined time points. Secondary outcomes included adverse events. Pooled proportions were calculated using random-effects models with logit transformation and Hartung-Knapp adjustment. Heterogeneity was assessed using the I² statistic. RESULTS: Four prospective studies (1 RCT, 3 prospective cohorts) comprising 118 patients were included. Studies were conducted in Norway (SECA-I, n = 21; SECA-II, n = 15), the United Kingdom (n = 50), and a European multicentre RCT (TransMet, n = 32). Median age ranged from 55 to 58 years; all patients had liver-only metastases with resected primary tumors and had received pre-transplant chemotherapy. The pooled 3-year OS was 69% (95% CI, 52-82%; I² = 0.0%), and the pooled 5-year OS was 62% (95% CI, 36-83%; I² = 14.6%). The pooled 3-year PFS was 33% (95% CI, 7-76%), with substantial heterogeneity (I² = 62.8%). The pooled incidence of adverse events was 41% (95% CI, 25-60%; I² = 0.0%). Sensitivity analyses confirmed the robustness of pooled estimates. The retrospective literature also supported the finding that LT can achieve meaningful long-term survival in carefully selected patients. CONCLUSIONS: In carefully selected patients with CRLM, LT is associated with durable long-term survival and an acceptable safety profile, supporting further prospective evaluation and refinement of selection criteria.
31 May 2026
Read appraisal →Journal of gastrointestinal cancer
Long-term Outcomes of Protocol-based Neoadjuvant Selection and Liver Transplantation Versus Liver Resection for Perihilar Cholangiocarcinoma: A Systematic Review and Meta-analysis
BACKGROUND: Perihilar cholangiocarcinoma (CCA) is an aggressive malignancy that presents significant challenges in terms of diagnosis and treatment owing to its anatomical location. Liver resection and transplantation are the primary curative options; however, their long-term outcomes remain controversial. This study aimed to compare the long-term outcomes of protocol-based neoadjuvant selection and liver transplantation with liver resection for the management of perihilar cholangiocarcinoma. METHODS: A systematic review and meta-analysis were conducted according to the PRISMA guidelines. Electronic databases, including the Cochrane Library, PubMed/MEDLINE, and Embase, were searched for relevant clinical trials comparing liver transplantation with liver resection. RESULTS: Six studies comprising 768 patients (265 in the liver transplantation group and 503 in the liver resection group) were included. Liver transplantation was associated with significantly higher 5-year overall survival and 5-year disease-free survival. They also showed a higher 3-year disease-free survival rate. Patients in the liver transplantation group had a higher R0 resection rate. There were no significant differences in the 3- or 30-day postoperative mortality between the two groups. CONCLUSION: Liver transplantation was associated with improved long-term survival in highly selected patients; however, these findings are limited by significant selection bias and the retrospective study design. The apparent long-term benefit observed with LT must be interpreted cautiously because transplant series frequently report post-transplant rather than intention-to-treat outcomes.
18 May 2026
Read appraisal →Nature communications
Donor-derived regulatory dendritic cell infusion and early immunosuppressive drug withdrawal in living-donor liver transplantation: a phase I/IIa trial
Operational tolerance (OT) following complete immunosuppression withdrawal (ISW) is rare ( ~ 13%) in eligible adult liver transplant recipients when initiated 1-2-years post-transplant. Regulatory dendritic cells (DCregs) promote transplant tolerance in pre-clinical models and attenuate immune effector cells in humans. Here, we completed a first-in-human phase I/IIa trial (2-year recruitment; 5 ± 0.5 years follow-up) to evaluate the feasibility, safety and preliminary efficacy of pre-emptive donor-derived DCreg (ddDCreg) infusion 7-days pre-transplant in 15 prospective living-donor liver recipients. Two patients were excluded from analysis for reasons unrelated to the study. ISW began one year post-transplant in candidates with a quiescent/permissive protocol biopsy. ddDCreg infusions were safe, reproducible, and well-tolerated. One-year post-transplant, 8/13 patients were eligible for ISW, 4 achieved complete ISW, 3 remained off all immunosuppression for >1 year. These 3 remained drug-free for 3.0 ± 0.17-years, reflecting a 37.5% OT rate in ISW-eligible recipients. Given the exploratory nature of this trial, additional studies to evaluate efficacy are needed. ClinicalTrials.gov registration number NCT03164265.
19 Apr 2026
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