April 2024

This post-hoc analysis of data from a randomized controlled trial found that patients who underwent the Ross procedure for aortic valve disease had excellent long-term survival compared to the general population as well as long-term freedom from reintervention. 

Summary: Aortic valve disease is the most common cause of valvular heart disease in the United States. Surgical aortic valve replacement (AVR) has been the standard of care for the management of aortic valve lesions not amenable to repair. Given the inherent limitations of bioprosthetic valves (limited lifetime durability) and mechanical valves (require lifelong anticoagulation), there has been considerable interest in the pursuit of better aortic valve substitutes. The Ross procedure is an operation that replaces the patient’s disease aortic valve with their own pulmonary valve (autograft) and implants a pulmonary valve homograft in the pulmonic position (homograft). This procedure is the only AVR operation that utilizes a living tissue valve substitute and has been shown to produce excellent hemodynamics, with limited valve-related complications and no need for lifelong anticoagulation. However, some studies have raised concerns about the technical complexity of the operation compared to standard AVR and the long-term durability of the pulmonary autograft in the aortic position. The present study is a post hoc analysis of clinical trial data aimed at evaluating long-term clinical and echocardiographic outcomes following the Ross procedure.

The study was a retrospective analysis of a single institution, randomized controlled trial that enrolled patients less than 69 years old with aortic valve disease requiring AVR from 1994 to 2001. In the initial trial, patients were randomized 1:1 to undergo AVR with either aortic valve homograft or Ross procedure. The trial included patients with concomitant aortic root or ascending aortic dilatation (>5 cm), bicuspid aortic valve disease, active endocarditis, rheumatic heart disease, decreased ejection fraction, or those who had previous cardiac surgery. Patients with Marfan’s syndrome, rheumatoid arthritis, and Reiter’s syndrome were excluded from the study. Of note, all Ross procedures were performed by a single surgeon using the same technique during the study period. The primary endpoint was long-term survival. Secondary endpoints include freedom from any valve-related reintervention (pulmonary autograft in aortic position or pulmonary homograft in pulmonic position) and longitudinal evaluation of autograft and homograft regurgitation, autograft root dimensions, and functional status at last follow-up. This post-hoc analysis only evaluated outcomes for the patients randomized to the Ross procedure in the initial trial, and therefore does not include comparative data on the patients randomized to aortic homograft.

A total of 108 patients (mean age 38 years, 85% male) were randomly assigned to the Ross procedure in the initial trial. The most common aortic valve pathology was isolated aortic insufficiency (n=49, 45%). Notably, one-third of patients underwent a previous AVR with either a homograft (n=24, 22%) or mechanical/bioprosthetic substitute (n=13, 12%). Overall survival in this cohort at 25-years from the time of the Ross procedure was 83% (95% CI, 75.5-91.2%) with only one perioperative death. This represents a 99.1% (95% CI 91.8-100%) relative survival when compared to age, sex, and country of origin matched controls in the general population. Freedom from any Ross-related reintervention at 25-years was 71.1% (95% CI 61.6-82%), with 17 patients (15.7%) requiring 18 reinterventions on their pulmonary autograft and 14 patients (13%) requiring 18 reinterventions on their pulmonary homograft. For those who underwent reintervention on the autograft, the most common indication was aortic insufficiency with or without neo-aortic root dilation. In comparison, indications for intervention on the pulmonary homograft were more varied, and included pulmonary stenosis (7 patients), endocarditis (5 patients), severe pulmonary insufficiency (2 patients), and undetermined cause (4 patients). Older age at time of operation was associated with a lower risk for any reintervention (HR 0.96, 95% CI 0.92-0.99, p=0.02) and for homograft reintervention (HR 0.93, 95% CI 0.88-0.99, p=0.02). Interestingly, preoperative severe aortic regurgitation and previous aortic valve interventions were not found to be associated with an elevated risk of valve reintervention after the Ross procedure. Finally, despite a slow yet steady progression of autograft insufficiency in this cohort, the majority of patients had mild or mild-to-moderate autograft insufficiency, stable neo-aortic root diameters, and normal left ventricular ejection fractions during the follow-up period. This study was, first and foremost, limited by small sample size. Similarly, since each surgery was performed by a single surgeon at a Ross center of excellence, these results should be interpreted with some caution until more data on this topic is accrued. 

Bottom line: The Ross procedure may provide excellent long-term durability and survival for select, younger patients undergoing AVR by an experienced surgeon and should be considered in surgical armamentarium to optimize the lifetime management of aortic valve disease.

This study uses workplace-based assessments to predict the probability that general surgery residents will be practice-ready to perform five common procedures at the time of graduation. The findings demonstrate substantial variation in graduating trainee competency and highlight the need for educational improvements to reduce this variation and ensure resident preparedness for independent surgical practice.

Summary:
There are growing concerns that general surgery residency programs are not adequately preparing residents to enter independent surgical practice. The Society for Improving Medical Professional Learning (SIMPL) app is a workplace-based assessment tool that allows attending surgeons to rate trainee’s operative performance. This study sought to examine operative competency of graduating trainees across common general surgery procedures.

A Bayesian-mixed effects model was trained on 63,248 assessments of 2,605 residents by 1,884 faculty at 70 general surgery programs using the SIMPL registry (2015-2021) for five procedures categories: appendectomy, cholecystectomy, inguinal and femoral (i.e., groin) hernia repair, ventral hernia repair, and partial colectomy. The SIMPL evaluation is an app-based assessment tool used to provide feedback to a trainee about a given operative experience, which are completed by attending physicians. This model was applied to 17,248 evaluations of 927 PGY5 residents from the same dataset to generate a predicted probability that a trainee would earn a practice-ready (or higher) evaluation for a given procedure the next time the trainee was assessed. For each procedure category, predicted competency rates were calculated as the percentage of residents achieving > 90% probability of being rated as practice-ready on the next procedure. Descriptive statistics were generated for predicted probabilities and the last documented SIMPL ratings within each procedure category.

Among the last documented SIMPL assessments, practice-ready (or higher) ratings were observed for 92.8% of appendectomy assessments, 89.3% for cholecystectomy, 81.3% for ventral hernia repair, 74.6% for groin hernia repair, and 70.1% for partial colectomy. However, predicted competency rates varied across procedure categories: 97.4% for appendectomy, 82.4% for cholecystectomy, 43.5% for ventral hernia repair, 24% for groin hernia repair, 5.3% for partial colectomy. The greatest variation by trainee in predicted probability was observed within the partial colectomy and groin hernia repair categories, with less variation within the appendectomy and cholecystectomy categories, and bimodal variation within the ventral hernia category. Notably, competency rates were predicted based on an individual trainee’s cumulative procedure-specific performance, so the model may have underestimated performance for residents with more SIMPL assessments from early training. Additionally, residents and faculty choose which cases to evaluate in SIMPL, which may introduce sampling bias.  

Bottom line: Substantial variation in the operative competency of graduating general surgery residents was observed for several common procedures. Both incremental improvements to surgical education and a broader transition to competency-based training may be a help decrease this variability and ensure trainee readiness for independent practice. 

This prospective observational study looked at the association between the presence of microplastic and nanoplastic particles (MNPs) in carotid plaques and cardiovascular outcomes in patients with carotid artery disease. They found that patients who had detectable microplastics and nanoplastics in their carotid plaque had a higher risk of stroke, myocardial infarction, or mortality compared to those where MNPs were not detected. 

Summary: Plastic production is escalating annually, which consequently has increased environmental contamination by pollution from plastics. As these plastics break down, they form microplastics, defined as particles under 5 mm and nanoplastics. those less than 1000 nanometers, which can infiltrate the human body through various pathways. Recently, these micro- and nanoplastics, collectively known as MNPs, have been implicated as a novel and potentially harmful risk factor for cardiovascular disease.  are formed and can enter the human body in various ways. 

In order to study this association between the burden of MNPs within carotid plaques and cardiovascular disease, a prospective, multicenter, observational study was conducted recruiting patients who were scheduled to undergo carotid endarterectomy for high-grade (>70%) asymptomatic carotid artery disease. A total of 304 patients were enrolled and 257 patients completed follow up visits. Excised carotid plaque specimens were analyzed for the presence of MNPs and proinflammatory markers. The primary end point was a composite outcome of nonfatal myocardial infarction, nonfatal stroke, or death from any cause. 

Of the 257 patients who completed follow-up, 150 patients (58.4%) had a detectable amount of polyethylene (21.7±24.5 μg per mg) in the excised plaque and 31 of those patients (12.1%) also had a measurable amount of polyvinyl chloride (5.2±2.4 μg per mg) in the excised plaque. Patients with evidence of MNPs were more often younger, male gender, smokers, had higher baseline creatinine levels and a higher prevalence of diabetes, cerebrovascular disease, and hyperlipidemia. There were no geographic differences in the incidence of MNPs. Stable isotope analysis showed lower δ13C values in plaque that had evidence of MNPs, which suggests the presence of petroleum-derived plastics. Plaque tissue proinflammatory biomarkers were analyzed by ELISA and immunohistochemical assay, which showed a correlation between their expression and the amount of polyethylene present. 

At max follow up time, the composite outcome occurred in 20% of patients with evidence of MNPs (30/150 patients) compared to 7.5% of patients without evidence of MNPs (8/105 patients). Overall, patients with MNPs in their plaque had 4.53 times the risk of cardiovascular event compared to those without MNPs in their plaque (HR 4.53, 95% CI: 2.0 - 10.3; p<0.001).

There are several limitations of this observational study as there are many possible confounders that were unable to be accounted for within the confines of this study, such as socioeconomic status, unknown lifetime exposure to plastics, food and drinking water source, and specimen contamination. Therefore, the authors cannot prove causality by this study alone. 

Bottom line: Micro- and nanoplastic particles have been detected in samples of carotid artery plaques and may be associated with cardiovascular events among patients with carotid artery disease.