Type A aortic dissection: optimal annual case volume for surgery

Mitral Valve Repair: Optimal Annual Case Volume for Surgery

BACKGROUND

Despite strong recommendations from multiple societies to pursue durable mitral valve repair (MVr), repair rates and outcomes remain inconsistent across the world. This is partly due to limited surgeon and center experience and lack of centralization of care for this technically challenging operation.

OBJECTIVES

The authors evaluate the association between annual case volume and contemporary long-term outcomes of patients undergoing isolated MVr.

METHODS

A systematic literature search was performed to identify contemporary studies on isolated MVr in adults from January 2013 to November 2023. The primary outcomes were long-term survival, freedom from reoperation, and freedom from recurrent mitral regurgitation (moderate-severe). A novel meta-analytic volume-outcome approach using reconstructed Kaplan-Meier-derived individual patient data from the original studies was used. A frailty Cox model was applied to study volume-outcome relationships. Studies were pooled for each reported outcome and divided into 3 tertiles (T1-3) based on the annual case volume and number of patients of each center.

RESULTS

A total of 14,070 patients from 60 studies were pooled. Sixteen studies (n = 6,099) reported long-term survival. The overall pooled 10-year survival was 70.8% (95% CI: 68.9%-72.8%). Compared to lower volume centers, centers performing >38 cases/y were associated with significantly improved long-term survival (HR: 0.42; 95% CI: 0.36-0.49; P < 0.001). For degenerative mitral valve disease, a volume cutoff of >45 cases/y was associated with significantly improved long-term survival (HR: 0.40; 95% CI: 0.32-0.49; P < 0.001). Twelve studies (n = 4,230) reported long-term freedom from reoperation and 10 studies (n = 2,470) reported Kaplan-Meier-derived long-term freedom from recurrent mitral regurgitation data, respectively. The overall pooled 10-year freedom from reoperation was 90.2% (95% CI: 88.1%-92.4%), while the overall pooled 10-year freedom from recurrent mitral regurgitation was 72.7% (95% CI: 68.9%-76.8%). Centers performing >45 cases/y (HR: 0.61; 95% CI: 0.44-0.84; P = 0.003) and >70 cases/y (HR: 0.64; 95% CI: 0.42-0.98; P = 0.042) were associated with significantly improved long-term freedom from recurrent mitral regurgitation and freedom from reoperation, respectively. For degenerative mitral disease, >45 cases/y was associated with significantly improved freedom from recurrent mitral regurgitation (HR: 0.51; 95% CI: 0.36-0.72; P < 0.001); the volume outcome association for freedom from reoperation was not statistically significant (P = 0.58).

CONCLUSIONS

Our study validates volume cutoffs associated with optimal long-term outcomes following isolated MVr. We found MVr volumes of >38 cases/y, 45 cases/y, and >70 cases/y to be associated with significantly improved long-term survival, durability of repair, and freedom from reoperation, respectively. These findings may define experienced centers and surgeons for patients requiring MVr for primary/degenerative mitral valve disease.

The optimal annual case volume for acute type A aortic dissection surgery in relation to long-term outcomes

OBJECTIVES

Previous analyses of the volume-outcome relationship have focused on short-term outcomes such as early mortality. The current study aims to update a novel statistical methodology, facilitating the evaluation of the relation between procedural volume and time-to-event outcomes such as long-term survival, using surgery for acute type A aortic dissection as an illustrative example.

METHODS

This study employed an existing dataset of type A dissection outcomes, retrieved from literature. Studies were included when reporting on annual case load and long-term survival, which served as the primary outcome of interest. Individual patient data were reconstructed from the included studies, and a hazard ratio was determined per study in relation to overall survival, after which the calculated hazard ratios were incorporated in a restricted cubic-spline model, facilitating the application of the elbow method.

RESULTS

Fifty-two studies were included (n = 14 878 patients), with a median follow-up of 5 years. One-, 3-, 5- and 10-year survival of the overall cohort were 82% [95% confidence interval (CI) 82-83%], 79% (95% CI 78-80%), 74% (95% CI 74-75%) and 60% (95% CI 59-62%), respectively. A significant non-linear volume-outcome relation for long-term survival was observed in both the unadjusted and adjusted analyses (P = 0.030 and P = 0.002), with an optimal annual case load of 32 cases/year (95% CI 31-33).

CONCLUSIONS

Based on the available data, these findings imply that the annual case volume to achieve optimal long-term survival is located near a procedural volume of 32 cases/year. After accrual of more annual procedures, long-term survival may no longer significantly improve any further.

The volume-outcome relationship for pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension

BACKGROUND

We conducted a volume-outcome meta-analysis of pulmonary endarterectomy procedures for chronic thromboembolic pulmonary hypertension to objectively determine the minimum required annual case load that can define a high-volume centre.

METHODS

Three electronic databases were systematically queried up to 1 May 2024. Centres were divided in volume tertiles. The primary outcomes were early mortality and long-term survival. Restricted cubic splines were used to demonstrate the volume-outcome relationship and the elbow-method was applied to define high-volume centres. Long-term survival was assessed using Cox frailty models.

RESULTS

We included 51 centres (52 consecutive cohorts) and divided them into tertiles (T1: <6 cases per year; T2: 6-15 cases per year, T3: >15 cases per year), comprising a total 11 345 patients (mean age 52.3 years). Overall early mortality was 6.0% (T1: 11.6%; T2: 7.2%; T3: 5.2%; p<0.001), for which a significant nonlinear volume-outcome relationship was observed (p=0.0437) with a statistically determined minimal required volume of 33 cases per year (95% CI 29-35 cases), and a modelled volume of 40 cases per year corresponding to a 5.0% mortality rate. Nevertheless, early mortality still progressively declined in higher volume centres (from 6.7% to 5.4% to 2.9% in centres performing 16-50, 51-100 and >100 procedures annually). In addition, a significant volume effect was observed for long-term survival (adjusted hazard ratio per tertile 0.75, 95% CI 0.63-0.89; p=0.001).

CONCLUSION

There is a significant association between procedural volume and early mortality in pulmonary endarterectomy. An annual procedural volume of >33-40 cases per year may be used to define a high‑volume centre, although higher volumes still lead to progressively lower mortality rates.

Short- and long-term outcomes in isolated vs. hybrid thoracoscopic ablation in patients with atrial fibrillation: a systematic review and reconstructed individual patient data meta-analysis

AIMS

Both isolated thoracoscopic and hybrid thoracoscopic atrial fibrillation (AF) ablation techniques have demonstrated favourable outcomes in the management of patients with (long-standing) persistent AF, as compared with catheter ablation. However, it is currently unknown whether there is a difference in short- and long-term outcomes when comparing these two minimally invasive surgical AF ablation procedures. Therefore, a systematic review and meta-analysis were performed to investigate these two techniques, with a specific emphasis on long-term freedom from atrial tachyarrhythmias (ATAs).

METHODS AND RESULTS

A systematic search through PubMed, EMBASE, and the Cochrane Library databases was performed. All studies reporting on short-term outcomes were included in the meta-analysis. A pooled analysis of long-term freedom from ATA was performed based on Kaplan-Meier (KM) curve-derived individual patient data. Reconstructed individual time-to-event data were analysed in a multivariable Cox frailty model with adjustments for age, sex, type of AF, duration of AF history, and study variable (frailty term in the frailty Cox model). In total, 53 studies were included in the meta-analysis, encompassing 4950 patients. There were no differences in major short-term outcomes (mortality or stroke) between isolated thoracoscopic and hybrid thoracoscopic ablation. A total of 18 studies reported KM curves for long-term freedom from ATA, comprising 2038 patients. Adjusted analysis revealed that hybrid ablation was significantly associated with greater freedom from ATA [adjusted hazard ratio (aHR) = 0.59, 95% confidence interval (CI): 0.43-0.83, P < 0.001] compared with isolated thoracoscopic ablation. Additionally, older age (aHR = 1.07, 95% CI: 1.03-1.12, P = 0.002) and a higher percentage of male patients (aHR = 1.02, 95% CI: 1.01-1.03, P < 0.001) were significantly associated with lower long-term freedom from ATA recurrence.

CONCLUSION

Hybrid thoracoscopic AF ablation is associated with a greater long-term freedom from ATA when compared with isolated thoracoscopic ablation, without differences in complications.

Defining the optimal annual institutional case volume for minimally invasive repair of pectus excavatum through a systematic review of literature and meta-analysis of outcomes

Background

The Nuss procedure is the accepted standard approach to correct pectus excavatum. Still, is associated with potential major complications that are in part believed to be preventable as they might be the consequence of institutional case-volume differences. The objective is to evaluate the presence of a volume-outcome relation for the Nuss procedure and determine the optimal annual institutional case-volume threshold, defining high-volume centers.

Methods

A systematic literature search was performed, considering studies from unique centers reporting on pectus excavatum patients who underwent the Nuss procedure. Primary and secondary outcomes were, respectively: the incidence of significant perioperative complications (Clavien-Dindo ≥ grade-III and significant intraoperative complications) and bar displacement. The presence of a non-linear volume-outcome relation was evaluated through restricted-cubic-spline-analyses. If present, the optimal annual institutional case-volume was determined by the elbow method.

Results

Forty-nine studies from 49 unique centers were included, enrolling 13,352 patients in total. The significant perioperative complication rate was low [7.7%, 95% confidence interval (CI): 6.4-9.0%] and demonstrated a significant non-linear volume-outcome relation (P<0.001), even after covariate adjustment. The optimal annual institutional case-volume was determined at 73 cases/year (95% CI: 67-89). In this scenario, the number needed to treat to prevent a single perioperative complication compared to a low volume center was 11 (95% CI: 8-19). A similar volume-outcome relation (P<0.001) and optimal case volume of 73 cases/year was observed for bar displacement.

Conclusions

A significant volume-outcome relation for repair of pectus excavatum by the Nuss procedure exists with an optimal annual institutional case-volume of 73 cases/year. These findings provide rationale for centralization.

Long-Term Results and Quality of Life after Surgery for Acute Aortic Dissection Type A: Contemporary Single-Centre Experience

Background: Aortic dissection is still afflicted with significant morbidity and mortality. This research seeks to assess long-term outcomes and quality of life after emergency surgery for acute aortic dissection type A. Methods: A total of 413 patients were analysed, who had been operated upon between 2000 and 2016 at our centre. We compared our results of the early (2000-2007) versus late (2008-2016) period with regards to 30-day and follow-up mortality and need for reoperation, including risk factor analysis. Quality of life was assessed via the SF-36 survey. Results: Calculated perioperative risk by EuroSCORE increased significantly from early, 24.9%, to late, 38.0%, p < 0.001. Thirty-day rates of mortality decreased significantly from 26.7% to 17.4%, p = 0.03. Survival at 1-, 5-, and 10-years was 92.3% vs. 91.8% (p = 0.91), 75.2% vs. 81.0% (p = 0.29), and 53.4% vs. 69.7% (p = 0.04). Freedom from reoperation was comparable between groups at follow-up: 74.0% vs. 85.7%, p = 0.28. Quality of life was impaired. Conclusions: Despite more complex severity of disease and operative procedures, the results of surgery for type A aortic dissection improved significantly over time at 30-day and 10-year follow-up. Quality of life was significantly impaired compared to a healthy reference population.

The Year in Aortic Surgery: Selected Highlights From 2023

This article reviews the recent and relevant literature to the field of aortic surgery. Specific areas highlighted include outcomes of Stanford type A dissection, management of acute aortic syndromes, management of aortic aneurysms, and traumatic aortic injury. Although the focus was on articles from 2023, literature from prior years also was included, given that this article is the first of a series. Notably, the pertinent sections from the 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management Aortic Disease are discussed.

Exploring the relationship between case volume and intracranial aneurysm treatments with flow-diverters and flow-disruptors: Insights from the 2020 to 2021 Database of the German Society for Interventional Radiology National Registry in Germany

BACKGROUND AND PURPOSE

Intracranial aneurysm treatment using flow-diverters and flow-disruptors requires a higher level of expertise when compared to more traditional methods. Our hypothesis was that the procedural success and the rate of complications are dependent on the annual case load of a center.

MATERIALS AND METHODS

Conducting a retrospective analysis on the Database of the German Society for Interventional Radiology for the years 2020 to 2021, we examined flow-diverter and flow-disruptor procedures. We categorized centers into four groups according to their annual case load and proceeded to analyze success rates, complication rates, and fluoroscopy times across these centers.

RESULTS

No statistically significant differences were observed among the groups in both flow-diverter and flow-disruptor cases concerning fluoroscopy time and the incidence of technical complications. However, within the subgroup of flow-disruptor cases, centers with lower case load exhibited significantly higher rates of hemorrhagic and clinically relevant complications. Additionally, it was noted that the rate of therapeutic success in the flow-diverter group significantly increased in centers with higher case volumes.

CONCLUSION

Our findings support the intention towards centralization of medical care especially for complex neuroendovascular procedures. Furthermore, our findings are an argument to further develop a standardized educational and procedural algorithm based on defined case numbers and training modules for complex neurovascular procedures as already implemented by the Database of the German Society for Interventional Radiology.