Preoperative Dialysis Research Articles

Intraoperative hypotension during critical phases of liver transplantation and its impact on acute kidney injury: a retrospective cohort study

IntroductionAcute Kidney Injury (AKI) following Liver Transplantation (LT) is associated with prolonged ICU and hospital stay, increased risk of chronic renal disease, and decreased graft survival. Intraoperative hypotension is a modifiable risk factor associated with postoperative AKI. We aimed to determine in which phase of LT hypotension has the strongest association with AKI: the anhepatic or neohepatic phase. MethodsThis retrospective cohort study included adult patients undergoing LT between January 2010 and June 2022. Exclusion criteria were re-do or combined transplantations, preoperative dialysis, and early graft failure or death. Primary outcome was AKI as defined by KDIGO. Hypotension was Mean Arterial Pressure (MAP) below predefined thresholds in minutes. Risk adjusted logistic regression analysis considered hypotension in 3 periods: the total procedure, anhepatic phase, and neohepatic phase. ResultsOur cohort included 1153 patients. The median MELD-NA score was 19 (IQR 11–28), and 412 (35.9%) were living-related donations. AKI occurred in 544 patients (47.2%). The unadjusted model showed an association with AKI for MAP < 60 mmHg (OR = 1.011 [1.0, 1.022], p = 0.047) and MAP < 55 mmHg (OR = 1.023 [1.002, 1.047], p = 0.04) in the anhepatic phase, and for MAP < 60 mmHg (OR = 1.032 [1.01, 1.056], p = 0.006) in the neohepatic phase. The adjusted model did not reach significance in the subgroups but did in the total procedure: MAP < 60 mmHg (OR = 1.005 [1.002, 1.008], p < 0.001) and MAP < 55 mmHg (OR = 1.008 [1.003–1.013], p = 0.004). ConclusionIntraoperative hypotension is independently associated with AKI following LT. This association is seen during the anhepatic phase. Maintaining MAP above 60 mmHg may improve kidney function after LT.

Impact of Chronic Kidney Disease on Outcomes following Vascular Procedure in the Vascular Quality Initiative.

Chronic kidney disease (CKD) increases morbidity and mortality in most vascular procedures. However, a binary classification of estimated glomerular filtration rate (eGFR) <60mL/min/1.73 m2, which is often used in both modeling and clinical trials, may not be optimal for predicting clinical outcomes. Determine the optimal eGFR cutoff for use in risk stratification and prediction models. Vascular Quality Initiative (VQI) data for non-emergent, first-time OAR, EVAR, TEVAR, CEA, CAS, PVI, Supra- and infra-inguinal bypass were analyzed from to 2013-2023 and divided into cohorts based on eGFR (≥60, 45-59, 30-44, <30, and preoperative dialysis). χ2 and logistic regression were used to evaluate perioperative outcomes. Compared to patients with eGFR ≥60, those with eGFR 45-59 had similar odds of mortality following all procedures, except TEVAR. Driven by this group, the combined cohort showed a slight increase in the odds of mortality for eGFR 45-59 (0.6% vs. 0.7%, aOR 1.16, P=0.002). Those in the 30-44 group demonstrated increased odds of mortality both overall and in the individual procedure groups (0.6% vs. 1.2%, aOR 1.78, P<0.001). The odds of mortality continued to increase with worsening eGFR. The overall rate of new permanent dialysis was low for all eGFR cohorts, with a 0.02% difference between those with eGFR >60 and those in the 45-59 cohort (0.04% vs. 0.06%; a OR 1.65, P<0.001). The odds of permanent dialysis likewise continued to increase with decreasing eGFR. Rather than a binary eGFR cutoff of ≥60 and <60 to stratify patient risk, better risk stratification may be achieved by using five groups of ≥60, 45-59, 30-44, <30, and preoperative dialysis.

Trends and predictors of laparoscopic compared with open emergent inguinal hernia repair

BackgroundLaparoscopic emergent inguinal hernia repair remains controversial despite studies suggesting it is safe and feasible. Variables associated with laparoscopic compared with open emergent inguinal hernia repair are currently not well described. This study aims to investigate patient characteristics and risk factors associated with laparoscopic emergent inguinal hernia repair. MethodsThe American College of Surgeons National Surgical Quality Improvement database was queried for adult patients (age ≥18 years) who had undergone emergent inguinal hernia repair between 2015 and 2021. The relationships between demographic variables and laparoscopic compared with open emergent inguinal hernia repair were evaluated using univariate and multivariate analyses. ResultsA total of 8,215 patients were included in this analysis. Use of laparoscopic emergent inguinal hernia repair increased from 9% in 2015 to 23% in 2021. Female patients (odds ratio, 1.84, P < .001) and patients aged ≤65 years (odds ratio, 1.25, P = .005) were more likely to undergo laparoscopic repair. Black (odds ratio, 0.73, P = .003) and Hispanic (odds ratio, 0.72, P = .006) patients and patients with greater American Society of Anesthesiologists classification (odds ratio, 0.86, P = .037), ascites (odds ratio, 0.39, P = .039), and preoperative dialysis requirement (odds ratio, 0.45, P = .017) were less likely to undergo laparoscopic repair. Aside from a decreased likelihood of readmission in patients who underwent laparoscopic surgery (odds ratio, 0.696, P = .024), there was no difference in other postoperative outcomes, despite a laparoscopic approach being associated with greater rates of concomitant procedures compared with an open approach (24% vs 18%, P < .001). ConclusionsFemale sex, younger age, and lower American Society of Anesthesiologists class were associated with a greater likelihood of laparoscopic surgery. Black and Hispanic patients and patients with ascites and dialysis requirements were less likely to undergo laparoscopic repair. Laparoscopic inguinal hernia repair can be safely performed in an emergent setting.

Derivation and validation of a risk calculator for the prediction of incidence of complications following repair of Achilles Tendon Rupture

BackgroundThe Achilles tendon is the body’s strongest and largest tendon. It is commonly injured, particularly among athletes, accounting for a significant portion of serious tendon injuries. Several factors play a precipitating role in increasing the risk of these injuries.ObjectiveOur objective is to derive and validate a risk calculator for the prediction of incidence of any complication following Achilles tendon repair.MethodsWe used de-identified data from the American College of Surgeons’ National Surgical Quality Improvement Project (NSQIP) database from 2005 to 2021. It comprises 7010 individuals who had undergone Achilles tendon rupture repair. Demographic and risk factors information was collected. To develop the calculator, the sample was divided into a derivation cohort (40%) and a validation cohort (60%). Multivariate logistic regression was used for statistical analysis, and a risk calculator for incidence of any complication was derived from the derivation cohort and validated on the remaining 60% of the sample. Patients with missing data were excluded, and the significance level was set at p < 0.05.ResultsWe analyzed the derivation cohort of 2245 individuals who underwent Achilles tendon repair surgery between 2005 and 2021, with a 5.5% overall complication. Multivariate logistic regression identified anesthesia type, ASA classification, certain co-morbidities (pre-operative dialysis and medication-requiring hypertension), and wound classification as significant predictors of complications. The developed risk calculator model had an area under the curve (AUC) of 0.685 in the derivation cohort and 0.655 in the validation cohort, surpassing the widely used and validated modified frailty index. A cut-off score threshold of 0.06 was established using Youden’s index to dichotomize individuals into low and high risk for developing any postoperative complications.ConclusionOur risk calculator includes factors that most significantly affect the incidence of any complication following Achilles tendon repair.

Serum from patients with cirrhosis undergoing liver transplantation induces permeability in human pulmonary microvascular endothelial cells ex vivo.

Patients with cirrhosis undergoing liver transplantation frequently exhibit systemic inflammation, coagulation derangements, and edema, indicating endothelial dysfunction. This syndrome may worsen after ischemia-reperfusion injury of the liver graft, coincident with organ dysfunction that worsens patient outcomes. Little is known about changes in endothelial permeability during liver transplantation. We hypothesized that sera from these patients would increase permeability in cultured human endothelial cells ex vivo. Adults with cirrhosis presenting for liver transplantation provided consent for blood collection during surgery. Sera were prepared at five time points spanning the entire operation. The barrier function of human pulmonary microvascular endothelial cells in culture was assessed by transendothelial resistance measured using the ECIS ZΘ system. Confluent cells from two different endothelial cell donors were stimulated with human serum from liver transplant patients. Pooled serum from healthy men and purified inflammatory agonists served as controls. The permeability response to serum was quantified as the area under the normalized resistance curve. Responses were compared between time points and analyzed for associations with clinical characteristics of liver transplant patients and their grafts. Liver transplant sera from all time points during surgery-induced permeability in both endothelial cell lines. The magnitude of permeability change was heterogeneous between patients, and there were differences in the effects of sera on the two endothelial cell lines. In one of the cell lines, the severity of liver disease was associated with greater permeability at the start of surgery. In the same cell line, serum collected 15 min after liver reperfusion induced significantly more permeability as compared to that collected at the start of surgery. Early postreperfusion sera from patients undergoing living donor transplants induced more permeability than sera from deceased donor transplants. Sera from two exemplary cases of patients on preoperative dialysis, and one patient with an unexpectedly long warm ischemia time of the liver graft, induced exaggerated and prolonged endothelial permeability. Serum from patients with cirrhosis undergoing liver transplantation induces permeability of cultured human pulmonary microvascular endothelial cells. Increased endothelial permeability during liver transplantation may contribute to organ injury and present a target for future therapeutics.

Perioperative serum syndecan-1 concentrations in patients who underwent cardiovascular surgery with cardiopulmonary bypass and its association with the occurrence of postoperative acute kidney injury: a retrospective observational study

BackgroundVarious factors can cause vascular endothelial damage during cardiovascular surgery (CVS) with cardiopulmonary bypass (CPB), which has been suggested to be associated with postoperative complications. However, few studies have specifically investigated the relationship between the degree of vascular endothelial damage and postoperative acute kidney injury (pAKI).The objectives of this study were to measure perioperative serum syndecan-1 concentrations in patients who underwent CVS with CPB, evaluate their trends, and determine their association with pAKI.MethodsThis was a descriptive and case‒control study conducted at the National University Hospital. Adult patients who underwent CVS with CPB at a national university hospital between March 15, 2016, and August 31, 2020, were included. Patients who were undergoing preoperative dialysis, had preoperative serum creatinine concentrations greater than 2.0 mg dl−1, who were undergoing surgery involving the descending aorta were excluded. The perioperative serum syndecan-1 concentration was measured, and its association with pAKI was investigated.ResultsFifty-two patients were included. pAKI occurred in 18 (34.6%) of those patients. The serum syndecan-1 concentration increased after CPB initiation and exhibited bimodal peak values. The serum syndecan-1 concentration at all time points was significantly elevated compared to that after the induction of anesthesia. The serum syndecan-1 concentration at 30 min after weaning from CPB and on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.10 [1.01 to 1.21], P = 0.03]; OR = 1.16 [1.01 to 1.34], P = 0.04]; and the cutoff values of the serum syndecan-1 concentration that resulted in pAKI were 101.0 ng ml−1 (sensitivity = 0.71, specificity = 0.62, area under the curve (AUC) = 0.67 (0.51 to 0.83)) and 57.1 ng ml−1 (sensitivity = 0.82, specificity = 0.56, AUC = 0.71 (0.57 to 0.86)). Multivariate logistic regression analysis revealed that the serum syndecan-1 concentration on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.02 [1.00 to 1.03]; P = 0.03).ConclusionThe serum syndecan-1 concentration at all time points was significantly greater than that after the induction of anesthesia. The serum syndecan-1 concentration on postoperative day 1 was significantly associated with the occurrence of pAKI.Trial registrationThis study is not a clinical trial and is not registered with the registry.

Perioperative management of facial reconstruction surgery in patients with end-stage renal disease undergoing dialysis.

The rising incidence of dialysis-dependent end-stage renal disease (ESRD) has underscored the need for collaboration between plastic surgeons and nephrologists, particularly concerning preoperative and postoperative management for facial reconstruction. This collaboration is essential due to a scarcity of comprehensive information in this domain. A study initiated in January 2015 involved 10 ESRD cases on dialysis undergoing Mohs micrographic surgery for facial skin cancer, followed by reconstructive surgery under general anesthesia. To ensure surgical safety, rigorous measures were enacted, encompassing laboratory testing, nephrology consultations, and preoperative dialysis admission. Throughout surgery, meticulous control was exercised over vital signs, electrolytes, bleeding risk, and pain management (excluding nonsteroidal anti-inflammatory drugs). Postoperative assessments included monitoring flap integrity, hematoma formation, infection, and cardiovascular risk through plasma creatinine levels. Adherence to the proposed guidelines yielded a notable absence of postoperative wound complications. Postoperative plasma creatinine levels exhibited an average decrease of 1.10 mg/dL compared to preoperative levels, indicating improved renal function. Importantly, no cardiopulmonary complications or 30-day mortality were observed. In ESRD patients, creatinine levels decreased significantly postoperatively compared to the preoperative levels (p< 0.05), indicating favorable outcomes. The consistent application of guidelines for admission, anesthesia, and surgery yielded robust and stable outcomes across all patients. In particular, the findings support the importance of adjusting dialysis schedules. Despite the limited sample size in this study, these findings underscore the effectiveness of a collaborative and meticulous approach for plastic surgeons performing surgery on dialysis-dependent patients, ensuring successful outcomes.

Predictors and Impact of Prolonged Vasoplegia After Continuous-Flow Left Ventricular Assist Device Implantation

BackgroundVasoplegia after cardiac surgery is associated with adverse outcomes. However, the clinical effects of vasoplegia and the significance of its duration after continuous-flow left ventricular assist device (CF-LVAD) implantation are less known. ObjectivesThis study aimed to identify predictors of and outcomes from transient vs prolonged vasoplegia after CF-LVAD implantation. MethodsThe study was a retrospective review of consecutive patients who underwent CF-LVAD implantation between January 1, 2005, and December 31, 2017. Vasoplegia was defined as the presence of all of the following: mean arterial pressure ≤65 mm Hg, vasopressor (epinephrine, norepinephrine, vasopressin, or dopamine) use for >6 hours within the first 24 hours postoperatively, cardiac index ≥2.2 L/min/m2 and systemic vascular resistance <800 dyne/s/cm5, and vasodilatory shock not attributable to other causes. Prolonged vasoplegia was defined as that lasting 12 to 24 hours; transient vasoplegia was that lasting 6 to <12 hours. Patient characteristics, outcomes, and risk factors were analyzed. ResultsOf the 600 patients who underwent CF-LVAD implantation during the study period, 182 (30.3%) developed vasoplegia. Mean patient age was similar between the vasoplegia and no-vasoplegia groups. Prolonged vasoplegia (n = 78; 13.0%), compared with transient vasoplegia (n = 104; 17.3%), was associated with greater 30-day mortality (16.7% vs 5.8%; P = 0.02). Risk factors for prolonged vasoplegia included preoperative dialysis and elevated body mass index. ConclusionsCompared with vasoplegia overall, prolonged vasoplegia was associated with worse survival after CF-LVAD implantation. Treatment to avoid or minimize progression to prolonged vasoplegia may be warranted.

High Prevalence of Adverse Social Determinants of Health in Dialysis Access Creation Patients in a Safety-Net Setting

Patients receiving dialysis access surgery are often exposed to adverse social determinants of health (SDH) that negatively impact their care. Our goal was to characterize these factors experienced by our arteriovenous dialysis access patients and identify differences in health outcomes based on their SDH. We performed a retrospective cohort study of all patients who underwent dialysis access creation (2017-2021) and were screened for SDH at a clinical visit (using THRIVE survey) implemented at an urban, safety-net hospital institution within one year of access creation. Demographics, procedural details, early postoperative outcomes, survey responses, and referral to our hospital's preventive food pantry were recorded. Univariable analysis and multivariable analyses were performed to assess for associations with key health outcomes. There were 190 patients who responded to the survey within one year of their operation. At least one adverse SDH was identified in 42 (22%) patients. Normalized to number of respondents for each question, adverse SDH identified were difficulty obtaining transportation to medical appointments (18%), food insecurity (16%), difficulty affording utilities (13%), difficulty affording medication (12%), unemployed and seeking employment (9%), unstable housing (7%), difficulty caring for family/friends (6%), and desiring more education (5%). There were 71 (37%) patients who received food pantry referrals. Mean age was 60 years and 38% of patients were female and 64% were Black. More than half of patients (57%) had a tunneled dialysis catheter (TDC) at the time of access creation. Dialysis accesses created were brachiocephalic (39%), brachiobasilic (25%), radiocephalic fistulas (16%), and arteriovenous grafts (14%). Thirty-day emergency department visits, 30-day readmissions, and 90-day mortality occurred in 23%, 21%, and 2%, respectively. On univariable and multivariable analyses, any adverse SDH determined on survey and food pantry referral were not associated with preoperative dialysis through TDCs, receiving non-autogenous dialysis access, 30-day emergency department visits and readmissions, or 90-day mortality. Nearly a quarter of dialysis access surgery patients at a safety-net hospital experienced adverse SDH and more than one-third received a food pantry referral. Most common difficulties experienced include difficulty obtaining transportation to medical appointments, food insecurity, and difficulty paying for utilities and medication. Although there were no differences in postoperative outcomes, the high prevalence of these adverse SDH warrants prioritization of resources in this population to ensure healthy equity and further investigation into their effects on health outcomes.

The International Consortium on Primary Graft Dysfunction: Redefining Clinical Risk Factors in the Contemporary Era of Heart Transplantation

Background: Primary Graft Dysfunction (PGD) is the leading cause of morbidity and mortality early after heart transplant (HT). The International Consortium on PGD is a multicenter collaboration dedicated to identifying the clinical risk factors for PGD in the contemporary era of HT. The objectives of the current report were to 1) assess the incidence of severe PGD in an international cohort, 2) evaluate the performance of the most validated PGD risk tool, the RADIAL score, in a contemporary cohort, and 3) redefine clinical risk factors for severe PGD in the current era of HT. Methods: This is a retrospective, observational study of consecutive adult HT recipients between 2010 and 2020 in 10 centers in the United States, Canada, and Europe. Patients with severe PGD were compared to those without severe PGD (comprising those with no, mild and moderate PGD). The RADIAL score was calculated for each transplant recipient. The discriminatory power of the RADIAL score was evaluated using receiver operating characteristic (ROC) analysis and its calibration was assessed by plotting the percentage of PGD predicted versus observed. To identify clinical risk factors associated with severe PGD, we performed multivariable mixed-effects logistic regression modeling to account for among-center variability. Results: A total of 2,746 patients have been enrolled in the registry to date, including 2,015 (73.4%) from North America, and 731 (26.6%) from Europe. 215 participants (7.8%) met the criteria for severe PGD. There was an increase in the incidence of severe PGD over the study period (p-value for trend by difference sign test = 0.004). The Kaplan Meier estimate for 1-year survival was 75.7% [95%CI 69.4-80.9%] in patients with severe PGD as compared to 94.4% [95% CI 93.5-95.2%] in those without severe PGD (log-rank p-value <0.001). The RADIAL score performed poorly in our contemporary cohort and was not associated with severe PGD with an AUC of 0.53 (95%CI 0.48-0.58). In the multivariable regression model, acute preoperative dialysis (OR 2.41, 95% CI 1.31 – 4.43), durable LVAD support (OR 1.77, 95% CI 1.13 – 2.77), and total ischemic time (OR 1.20 for each additional hour, 95% CI 1.02 – 1.41) were associated with an increased risk of severe PGD. Conclusions: Our consortium has identified an increasing incidence of PGD in the modern transplant era. We identified contemporary risk factors for this early post-transplant complication, which confers a high mortality risk. These results may enable the identification of patients at high risk for developing severe PGD in order to inform peri-transplant donor and recipient management practices.

Risk Factors for Acute Kidney Injury after Moderate Hypothermic Circulatory Arrest in Hemiarch Replacement

Background. The aim of this study was to clarify the incidence and risk factors for acute kidney injury (AKI) in patients undergoing hemiarch replacement (HAR) under moderate hypothermic circulatory arrest (MHCA) with retrograde cerebral perfusion (RCP). Methods. We retrospectively analyzed patients who underwent HAR under MHCA with RCP at our institution between April 2015 and July 2022. Exclusion criteria were preoperative dialysis, single kidney, and lack of preoperative plasma creatinine data. The study endpoint was the incidence of postoperative AKI, defined using the Kidney Disease: Improving Global Outcomes criteria. Multivariate logistic regression analysis was performed to identify the risk factors for postoperative AKI. Results. One hundred and seventy-nine patients were included in this study. The most common indications for HAR were thoracic aortic aneurysm (n = 107) and acute aortic dissection (n = 57). Concomitant procedures, most frequently aortic valve surgery, were performed in 104 (60.5%) patients. Median circulatory arrest time and minimum rectal temperature were 15 minutes (interquartile range, 11 to 19) and 27.4°C (interquartile range, 25.9 to 28.1), respectively. Operative mortality was 1.1%. The incidence of postoperative AKI was 37.8%. Multivariate analysis showed that acute aortic dissection (odds ratio, 4.57; 95% confidence interval (CI), 2.13–10.14; P &lt; 0.001) and longer operating time (odds ratio, 1.01; 95% CI, 1.00-1.01; P = 0.001) were independent predictors for postoperative AKI. Conclusions. Acute aortic dissection and longer operating time were risk factors for postoperative AKI in patients undergoing HAR under MHCA with RCP. In contrast, neither circulatory arrest time nor minimum rectal temperature was a risk factor for AKI. This may be due to the short duration of circulatory arrest.

Tricuspid surgery at time of mitral surgery improves survival free from severe tricuspid regurgitation but not quality of life

ObjectiveThe choice to operate on moderate tricuspid regurgitation (TR) during mitral surgery is challenging owing to limited mid-term data. We assess whether concomitant tricuspid operations improve mid-term quality of life, morbidity, or mortality. MethodsAn institutional database identified mitral surgery recipients with moderate TR at the time of surgery from 2010 to 2019. Patients were stratified by the presence of a concomitant tricuspid operation. Quality of life at the last follow-up was assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Morbidity was compared using the χ2 test, Mann-Whitney U test, and Student t test. Survival was analyzed with Kaplan-Meier estimation. ResultsOf 210 mitral surgery recipients, 67 (31.9%) underwent concomitant tricuspid surgery. The concomitant tricuspid surgery cohort had greater preoperative dialysis use (10.5% vs 3.5%; P = .043) but similar age, New York Heart Association class, and cardiac surgery history relative to the nonconcomitant cohort (P > .05 for all). The concomitant tricuspid surgery cohort had a longer cardiopulmonary bypass time (144 minutes vs 122 minutes; P = .005) but a similar rate of mitral repair (P = .220). Postoperative KCCQ-12 scores reflected high quality of life in both cohorts (95.1 vs 89.1; P = .167). The concomitant tricuspid surgery cohort trended toward a higher perioperative pacemaker placement rate (22.8% vs 12.7%; P = .088) but were less likely to develop severe TR (0.0% vs 13.0%; P = .004). Overall survival was comparable between the 2 cohorts at 1 year (84.9% vs 81.6%; P = .628) and 5 years (73.5% vs 57.9%; P = .078). Five-year survival free from severe TR was higher in the concomitant cohort (73.5% vs 54.3%; P = .032). ConclusionsConcomitant tricuspid surgery for moderate TR is associated with increased 5-year survival free from severe TR but not with increased quality of life.

Comparative Study of Male and Female Patients Undergoing Frozen Elephant Trunk Total Arch Replacement.

Our aim was to investigate outcomes and long-term survival in male and female patients after frozen elephant trunk (FET) total arch replacement. Between March 2013 and January 2023, 362 patients underwent aortic arch replacement via the FET technique. We compared patient characteristics and intra- and postoperative data between male and female patients. Male patients were significantly younger (p = 0.012) but revealed a higher incidence of coronary artery disease (p = 0.008) and preoperative dialysis (p = 0.017). More male patients presented with type A aortic dissections (p = 0.042) while more female patients had aortic aneurysms (p = 0.025). The aortic root was replaced in significantly more male patients (p = 0.013), resulting in significantly longer cardiopulmonary bypass duration (p < 0.001) and operative times (p < 0.001). There were no statistically significant differences in postoperative outcome parameters including in-hospital mortality (p = 0.346). However, new in-stent thrombus formation was significantly more frequent in female patients (p = 0.002). Age in years (odds ratio (OR): 1.026, p = 0.049), an acute pathology (OR: 1.941, p = 0.031) and preoperative dialyses (OR: 3.499, p = 0.010) were predictive for long-term mortality in our Cox regression model, sex (p = 0.466) was not. There was no statistical difference in overall survival (log rank: p = 0.425). Female patients are older but reveal fewer cardiovascular risk factors; aneurysms are more common in female than male patients. As female patients undergo concomitant surgical procedures less often, their operative times are shorter. While survival and outcomes were similar, female patients suffered from postoperative new in-stent thrombus formation significantly more often.

Outcomes of double-valve surgery for infective endocarditis are improving in the modern era

BackgroundThe incidence of infective endocarditis (IE) is rapidly increasing. Contemporary outcomes following high-risk double valve surgery (DVS) for IE are not well described. MethodsBetween 2001 and 2021, 211 patients with IE underwent combined aortic and mitral valve surgery at a tertiary care referral center. Data from the Society of Thoracic Surgeons registry, including demographics, operative details, and outcomes, were collected. Risk factors for 30-day and 1-year-mortality were analyzed. Survival was analyzed using Kaplan-Meier and Cox proportional hazards modeling. ResultsThe study cohort had a male preponderance (73%), with a median age of 56 years (interquartile range [IQR], 44 to 63 years). Forty-five patients (21%) had a history of intravenous (IV) drug abuse, 50 (24%) were on preoperative dialysis, and 50 (24%) had prosthetic valve endocarditis. Thirty-day and 1-year mortality were 14% (n = 30) and 30% (n = 61), respectively. On multivariable Cox regression adjusting for age, prosthetic valve endocarditis, postoperative intra-aortic balloon pump (IABP), history of dialysis (adjusted hazard ratio [aHR], 1.9; 95% confidence interval [CI], 1.3 to 2.9; P = .002) and IV drug abuse (aHR, 2.0; 95% CI, 1.1-3.5; P = .02) were predictive of decreased survival. Undergoing surgery after 2010 was predictive of improved survival (aHR, 0.5; 95% CI, 0.3 to 0.8; P = .006). These patients were more likely to undergo urgent/emergent surgery (83% vs 29%; P < .001) and less likely to have an aortic root abscess (40% vs 58%; P = .03) or to require the commando procedure (13% vs 33%; P = .002). ConclusionsIn this large series evaluating outcomes of DVS for IE in the modern era, although the mortality risk remained elevated, improving outcomes may be associated with earlier surgical intervention before significant disease progression. Multidisciplinary evaluation for complex IE may be considered to better understand the optimal timing and repair strategy.

Machine learning to predict outcomes following endovascular abdominal aortic aneurysm repair.

Endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) carries important perioperative risks; however, there are no widely used outcome prediction tools. The aim of this study was to apply machine learning (ML) to develop automated algorithms that predict 1-year mortality following EVAR. The Vascular Quality Initiative database was used to identify patients who underwent elective EVAR for infrarenal AAA between 2003 and 2023. Input features included 47 preoperative demographic/clinical variables. The primary outcome was 1-year all-cause mortality. Data were split into training (70 per cent) and test (30 per cent) sets. Using 10-fold cross-validation, 6 ML models were trained using preoperative features with logistic regression as the baseline comparator. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Some 63 655 patients were included. One-year mortality occurred in 3122 (4.9 per cent) patients. The best performing prediction model for 1-year mortality was XGBoost, achieving an AUROC (95 per cent c.i.) of 0.96 (0.95-0.97). Comparatively, logistic regression had an AUROC (95 per cent c.i.) of 0.69 (0.68-0.71). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.04. The top 3 predictive features in the algorithm were 1) unfit for open AAA repair, 2) functional status, and 3) preoperative dialysis. In this data set, machine learning was able to predict 1-year mortality following EVAR using preoperative data and outperformed standard logistic regression models.

Risk factors for readmission after isolated coronary bypass graft surgery: context matters

Abstract Funding Acknowledgements Type of funding sources: None. Background Risk prediction scores are primarily based on preoperative factors and most applicable to their country of origin. Factors that contribute to these scores are commonly used to predict risk of readmission that is also highly variable. A recent systematic review of risk factors for unplanned readmission after first time isolated coronary artery bypass grafting (CABG)1 included cohort studies from the USA alone. Purpose To contrast risk factors for unplanned readmission in an Australian cohort with those identified in the systematic review. Methods A single centre, retrospective cohort analysis of adult patients from a major metropolitan tertiary teaching hospital having first time isolated CABG (N = 6155) between August 2002 and 2022. Unplanned inpatient readmission within 30-days of surgery was the primary outcome measure. Direct entry logistic regression modelling was used to identify risk factors for readmission in this cohort. Results The rate of readmission was 10.6% (n = 655). Female sex (OR 1.0, 95%CI 1-1.01), preoperative dialysis (OR 3.3, 95%CI 2.19-5.12), preoperative atrial fibrillation (OR 1.4, 95%CI 1.06-1.87), diabetes (OR 1.22, 95%CI 1.03-1.45), and peripheral vascular disease (OR 1.3, 95%CI 1.05-1.67) were the only significant predictors retained in the full model (c2(27, N = 6155) = 111.28, p &amp;lt;0.001) that correctly classified 89.3% of cases but only explained 3.6% (Nagelkerke R squared) of variation in readmission rate. The Hosmer-Lemeshow goodness of fit test indicated good support for the model despite this (p 0.841). Conclusion(s): Risk factors predicting readmission in this patient cohort were not consistent with those identified in the review of studies from the USA. Risk prediction is context specific. Research investigating factors associated with risk needs to capture variables that impact on context.

The use of anti-adrenergic agents as a predictor of acute kidney injury and delayed recovery of kidney function: the NARA-AKI cohort study.

Association of preoperative regular use of anti-adrenergic agents with postoperative acute kidney injury (AKI) and with trajectory of kidney function after AKI is still unknown. In a retrospective cohort study, adults undergoing non-cardiac surgery under general anesthesia were included. Obstetric or urological surgery, missing data, or preoperative dialysis was excluded. The exposure of interest was preoperative regular use of anti-adrenergic agents. The outcomes were AKI within 1 week postoperatively and trajectories of kidney function within 2 weeks postoperatively among patients with AKI. Multivariable logistic regression models were used to examine the association of anti-adrenergic agents with AKI. Linear mixed-effects models were used to compare the trajectories of postoperative kidney function after AKI between patients with and without anti-adrenergic agents. Among 5168 patients, 245 had used anti-adrenergic agents. A total of 309 (6.0%) developed AKI, and the use of anti-adrenergic agents was independently associated with postoperative AKI even after adjustment for preoperative and intraoperative potential confounders [odds ratio (95% confidence interval): 1.76 (1.14-2.71)]. The association was similar across preexisting hypertension or cardiovascular disease. Analyses restricted to patients with AKI suggested that the timing and stage of AKI were similar among those with and without anti-adrenergic agents; however, the recovery of kidney function was delayed among those with anti-adrenergic agents (P for interaction = 0.004). The use of anti-adrenergic agents was associated with postoperative AKI and delayed recovery of kidney function after AKI. Temporary withdrawal of anti-adrenergic agents during perioperative periods may contribute to prevent AKI and shorten the duration of AKI.

Review of prognostic factors for kidney transplant survival.

Transplantation is the most effective treatment for end-stage chronic kidney disease, as this procedure prolongs and improves the patient's quality of life. One of the key problems is the risk of graft rejection. The purpose of this research was to identify and analyse prognostic factors that will prevent rejection. In particular, the prognostic factors grouped by methods of synthesis, generalisation and statistical processing with calculation and graphical representation of hazard ratio and correlation coefficient were grouped, namely: age of donor and recipient, time of cold kidney ischaemia, duration of preoperative dialysis, body mass index, presence of concomitant diseases (diabetes mellitus, hypertension), primary causes causing transplantation. Several molecular genetic and biochemical prognostic markers (transcription factors, immunocompetent cell signalling and receptors, cytostatin C, creatinine, citrate, lactate, etc.) are annotated. It has been demonstrated that creatinine reduction rate determines the risk of rejection, displaying the dynamics of cystatin C and creatinine changes in the postoperative period. Young recipients who underwent prolonged preoperative dialysis were identified as having the highest risk of rejection. Diabetes and hypertension bear a non-critical but commensurately equal risk of rejection. The survival rate of the graft is better when transplanted from a living donor than from a deceased donor. A correlation between cold ischaemia time, body mass index and the probability of graft failure has been proven, namely, the greater the donor and recipient body mass index and the longer the cold ischaemia time, the lower the chance of successful long-term organ acclimation. The data obtained can be used as prognostic factors for graft accommodation at different intervals after surgery.

Development and Validation of a Prediction Score for Low-Cardiac-Output Syndrome After Adult Cardiac Surgery

The authors aimed to develop a simple prediction score to help identify patients at high risk of low-cardiac-output syndrome after adult cardiac surgery. A single-center, retrospective, observational study. At a tertiary hospital. Adult patients who underwent on-pump cardiac surgery between April 2016 and March 2021. None. Among the 2,806 patients retained for final analyses, 355 (12.7%) developed low-cardiac-output syndrome. Using a stepwise backward variable selection procedure applied to a multivariate logistic regression, a prediction model, including 8 risk factors, could be identified-preoperative left ventricular ejection fraction, glomerular filtration rate <60 mL/min according to the Cockcroft formula or preoperative dialysis, combined surgery, nonelective surgery, mitral valve surgery for mitral valve regurgitation, history of extracardiac arteriopathy, preoperative hemoglobin <13 g/dL, and New York Heart Association functional class III or IV. A clinical prediction score was derived from the regression coefficients. The model had a good discriminative ability, with an area under the receiver operating characteristics curve of 0.8 (95% CI: 077-0.84). Using a threshold value of 5, the score had a 68% sensitivity, 79% specificity, a positive-predictive value of 33%, and a negative-predictive value of 94%. These results were validated on a validation sample using the bootstrap resampling technique. The authors developed a clinical score to facilitate the prediction of low- cardiac-output syndrome after adult cardiac surgery. This could help tailor patient management by contributing to the early identification of those at high risk of postoperative low cardiac output.

Oxygen Delivery Thresholds During Cardiopulmonary Bypass and Risk for Acute Kidney Injury

BackgroundPostoperative acute kidney injury (AKI) in cardiac surgery patients is multifactorial and associated with low oxygen delivery (DO2) during cardiopulmonary bypass. MethodsCardiac surgical patients undergoing full cardiopulmonary bypass between May 1, 2016 and December 31, 2021 were included, whereas those on preoperative dialysis, undergoing circulatory arrest procedures, or lacking minute-to-minute physiologic data were excluded. A 5-minute running average of indexed DO2 (DO2i, mL/min/m2) was calculated ([pump flow] × [hemoglobin] × 1.36 [hemoglobin saturation] + 0.003 [arterial oxygen tension]/body surface area). AKI was defined using established Kidney Disease: Improving Global Outcomes criteria. The threshold of nadir DO2i on the effect of AKI was estimated using risk-adjusted Constrained Broken-Stick models. ResultsPostoperative AKI occurred among 1155 patients (29.4%), with 276 (7.0%) having stage 2 to 3 AKI. The median nadir DO2i was lower for those with (vs without) AKI (197.9 mL/min/m2 [interquartile range {IQR}, 166.3-233.2] vs 217.2 mL/min/m2 [IQR, 184.5-252.2], P < .001) and stage 2 to 3 AKI relative to stage 1 or none (186.9 mL/min/m2 [IQR, 160.1-220.5] vs 213.8 mL/min/m2 [IQR, 180.4-249.4]). In risk-adjusted analyses the estimated threshold for nadir DO2i was 231.2 mL/min/m2 (95% CI, 173.6-288.8) for any AKI and 103.3 (95% CI, 68.4-138.3) for stage 2 to 3 AKI. ConclusionsDecreasing nadir DO2i was associated with an increased risk of AKI. The identified nadir DO2i thresholds suggest management and treatment of nadir DO2i during cardiopulmonary bypass may decrease a patient’s postoperative AKI risk.