Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: 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. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

A Short Series of Laparoscopic Mesenteric Bypasses for Chronic Mesenteric Ischemia

Background: Laparoscopic aortomesenteric bypass may be performed to treat the chronic mesenteric ischemia patients who are not suitable for endovascular treatment. This study presents an initial experience with a limited series of laparoscopic mesenteric artery revascularization for the treatment of mesenteric ischemia. Methods: Chronic mesenteric ischemia (CMI) patients with previous unsuccessful endovascular treatment or with arterial occlusion and extensive calcification precluding safe endovascular treatment were offered laparoscopic mesenteric revascularization. From October 2015 until November 2018, nine patients with CMI underwent laparoscopic revascularization. In addition to demographic data and perioperative results of the treatment, graft patency was assessed with Duplex ultrasound at 1, 3, 6 and 12 months, and annually thereafter. A descriptive analysis of the data was performed. Results: All bypasses were constructed with an 8 mm ring enforced expanded polytetrafluoroethylene graft in a retrograde fashion (from infrarenal aorta or iliac artery) to either superior mesenteric artery or splenic artery (2 cases). Median operation time was 356 mins (range 247– 492 mins). Five patients had a history of unsuccessful endovascular treatment. Laparoscopic technical success was 78%, and the primary open conversion rate was 22%. All laparoscopic revascularization procedures remained patent after discharge during a median follow-up time of 26 months (range 18– 49 months). The primary graft patency at 30 days was 78%. Primary assisted, and secondary graft patency was 78% and 100%, respectively. Median weight gain was 2 kg (range 2– 18 kg), and all patients achieved relief from postprandial pain and nausea. No mortality was observed during the follow-up period. Conclusion: Laparoscopic aortomesenteric revascularization procedures for chronic mesenteric ischemia are feasible but require careful patient selection. These procedures should only be performed at referral centers by vascular surgeons with prior experience in laparoscopic vascular surgery

Cost-utility analysis comparing laparoscopic vs open aortobifemoral bypass surgery

Objectives: Laparoscopic aortobifemoral bypass has become an established treatment option for symptomatic aortoiliac obstructive disease at dedicated centers. Minimally invasive surgical techniques like laparoscopic surgery have often been shown to reduce expenses and increase patients’ health-related quality of life. The main objective of our study was to measure qualityadjusted life years (QALYs) and costs after totally laparoscopic and open aortobifemoral bypass. Patients and methods: This was a within trial analysis in a larger ongoing randomized controlled prospective multicenter trial, Norwegian Laparoscopic Aortic Surgery Trial. Fifty consecutive patients suffering from symptomatic aortoiliac occlusive disease suitable for aortobifemoral bypass surgery were randomized to either totally laparoscopic (n=25) or open surgical procedure (n=25). One patient dropped out of the study before surgery. We measured health-related quality of life using the EuroQol (EQ-5D-5L) questionnaire at 4 different time points, before surgery and for 6 months during follow-up. We calculated the QALYs gained by using the area under the curve for both groups. Costs were calculated based on prices for surgical equipment, vascular prosthesis and hospital stay. Results: We found a significantly higher increase in QALYs after laparoscopic vs open aortobifemoral bypass surgery, with a difference of 0.07 QALYs, (p=0.001) in favor of laparoscopic aortobifemoral bypass. The total cost of surgery, equipment and hospital stay after laparoscopic surgery (9,953 €) was less than open surgery (17,260 €), (p=0.001). Conclusion: Laparoscopic aortobifemoral bypass seems to be cost-effective compared with open surgery, due to an increase in QALYs and lower procedure-related costs. Keywords: laparoscopy, aortobifemoral bypass, cost-utility, quality-adjusted life years, QALYs, EQ-5D, health-related quality of life, HRQoL, cost-effectivenes

Patient-perceived health-related quality of life before and after laparoscopic aortobifemoral bypass

Background: In patients operated with laparoscopic aortobifemoral bypass (LABFB) for atherosclerotic obstruction in aortoiliac segment, the main focus of the reports published during the last two decades has been morbidity and mortality. The primary objective of this study was to examine the health-related quality of life (HRQL) in these patients before and after LABFB. Patients and methods: Fifty consecutive patients (27 females) with Trans-Atlantic Inter-Society Consensus II, type D lesions were prospectively included. Short-Form 36 (SF-36) questionnaire was used to get information about the HRQL before LABFB and at 1, 3 and 6 months after the operation. Main indication for LABFB was intermittent claudication. Linear mixed-effect models were used to assess changes in HRQL over time. Age, gender, smoking, blood loss, operation time, concomitant operation, the American Society of Anesthesiologists category, length of hospital stay, previous vascular procedures and aorta cross-clamping were used as fixed factors and their impact on the physical components of the SF-36, as well as the summary scores were determined with univariate analysis. Variables with P<0.2 were included in the multivariate regression analysis. P<0.05 was considered statistically significant. Results: Statistically significant improvement was found in all SF-36 domains as well as in the summary scores after LABFB compared to the preoperative scores. The improvement in scores was substantial already at 1 month and the effect was maintained at 3 and 6 months survey time points. Concomitant operations had a statistically significant negative impact on the physical components of SF-36. Data completeness of item questionnaires was 93% in the whole material. Reliability scale and homogeneity estimates for the eight domains had high internal consistency. Conclusion: Patients operated with LABFB for Trans-Atlantic Inter-Society Consensus II, type D lesions have reduced HRQL. LABFB leads to substantial and statistically significant improvement in the patients’ HRQL, when examined with SF-36. These results need to be replicated by a randomized clinical trial

Cost comparison analysis of laparoscopic versus open aortobifemoral bypass surgery: A randomized controlled trial

Background: Laparoscopic aortobifemoral bypass (LABFB) surgery has become an established treatment procedure for aortoiliac occlusive disease (AIOD), Trans-Atlantic Inter-Society Consensus II (TASC II), type D lesions. However, studies with an economic evaluation of this procedure are sparse. The main purpose of our study was to compare the costs of LABFB and open aortobifemoral bypass (OABFB) surgery. Patients and methods: This is a substudy of a larger randomized controlled prospective multicenter trial, Norwegian Laparoscopic Aortic Surgery Trial (NLAST). Perioperative data were collected on 70 patients undergoing surgery for AIOD, TASC type D lesions. Thirty-four patients were randomized to LABFB and 36 patients to OABFB. Treatment costs were calculated for the two operative treatments until 30 postoperative days. In addition to fixed and variable costs, direct and indirect costs were also included. Results: The mean total cost of LABFB was 19,798 € and for OABFB 34,016 € until 30 postoperative days. Laparoscopic procedure was 14,218 € less costly than the open procedure. The main factor leading to less cost of LABFB was shorter length of hospital stay (mean 5.3 days, 95% CI 4.1–6.5) as compared to OABFB (mean 10.1 days, 95% CI 7.5–12.6). Ten patients, three in the LABFB and seven in the OABFB group, had complications that resulted in reoperations within the 30 postoperative days. The mean cost of treatment for the complicated patients was 49,349 € and 82,985 €, respectively, for LABFB and OABFB. Conclusion: Laparoscopic aortobifemoral bypass procedure costs less than open aortobifemoral bypass for the treatment of advanced aortoiliac occlusive disease

Perioperative humoral stress response to laparoscopic vs open aortobifemoral bypass surgery

Minimally invasive surgery seems to reduce hormonal stress response to surgery, but has not previously been examined in major abdominal vascular surgery. Aortic cross-clamping time and operation time is known to be longer in the totally laparoscopic aortobifemoral bypass (LABF) as compared to open aortobifemoral bypass (OABF). The main objective of our study was to measure the hormonal stress response during surgery and aortic cross-clamping in patients undergoing a totally laparoscopic versus an open aortobifemoral bypass. This was a sub-study of a larger randomized controlled multicentre trial. Thirty consecutive patients with severe aortoiliac occlusive disease were randomized to either a laparoscopic (LABF) or an open (OABF) procedure. The surgical stress response was measured by perioperative monitoring of adrenocorticotropic hormone (ACTH), aldosterone, metanephrine and cortisol at eight different time-points. During surgery. there was an increase in all humoral stress markers in both groups. The analysis of covariance showed increased levels of cortisol and ACTH in open group at 24 h time-point as compared to the baseline and this difference was statistically significant between the two groups, which indicate an earlier return to baseline levels in the laparoscopic group. Results from the General Estimated Equations (GEE) model indicate that LABF generates a lower level of metanephrine and higher level of aldosterone as compared to OABF. In conclusion, although they have higher levels of ACTH, aldosterone and cortisol during surgery, the patients operated with a laparoscopic aortobifemoral bypass achieve earlier hormonal homeostasis after surgery compared to open aortobifemoral bypass. This is an Accepted Manuscript of an article published by Taylor & Francis, available online: http://www.tandfonline.co