Association of Elective Surgical Volume With State Executive Order Curtailing Elective Surgery in Michigan During the COVID-19 Pandemic.

OBJECTIVE: Our objective was to evaluate changes in elective surgical volume in Michigan while an executive order (EO) was in place curtailing elective surgery during the COVID-19 pandemic. SUMMARY BACKGROUND DATA: Many state governors enacted EOs curtailing elective surgery to protect scare resources and generate hospital capacity for patients with COVID-19. Little is known of the effectiveness of an EO on achieving a sustained reduction in elective surgery. METHODS: This retrospective cohort study of data from a statewide claims-based registry in Michigan includes claims from the largest private payer in the state for a representative set of elective operations on adult patients from February 2 through August 1, 2020. We reported trends in surgical volume over the period the EO was in place. Estimated backlogs in elective surgery were calculated using case counts from the same period in 2019. RESULTS: Hospitals achieved a 91.7% reduction in case volume before the EO was introduced. By the time the order was rescinded, hospitals were already performing elective surgery at 60.1% of pre-pandemic case rates. We estimate that a backlog of 6419 operations was created while the EO was in effect. Had hospitals ceased elective surgery during this period, an additional 18% of patients would have experienced a delay in surgical care. CONCLUSIONS: Both the introduction and removal of Michigan's EO lagged behind the observed ramp-down and ramp-up in elective surgical volume. These data suggest that EOs may not effectively modulate surgical care and could also contribute to unnecessary delays in surgical care.

Assessment of Patterns of Atherectomy Use.

Background Atherectomy has become the fastest growing catheter-based peripheral vascular intervention performed in the United States, and overuse has been linked to increased reimbursement, but the patterns of use have not been well characterized. Methods and Results We used Blue Cross Blue Shield of Michigan Preferred Provider Organization and Medicare fee-for-service professional claims data from the Michigan Value Collaborative for patients undergoing office-based laboratory atherectomy in 2019 to calculate provider-specific rates of atherectomy use, reimbursement, number of vessels treated, and number of atherectomies per patient. We also calculated the rate that each provider converted a new patient visit to an endovascular procedure within 90 days. Correlations between parameters were assessed with simple linear regression. Providers completing ≥20 office-based laboratory atherectomies and ≥20 new patient evaluations during the study period were included. A total of 59 providers performing 4060 office-based laboratory atherectomies were included. Median professional reimbursement per procedure was $4671.56 (interquartile range [IQR], $2403.09-$7723.19) from Blue Cross Blue Shield of Michigan and $14 854.49 (IQR, $9414.80-$18 816.33) from Medicare, whereas total professional reimbursement from both payers ranged from $2452 to $6 880 402 per year. Median 90-day conversion rate was 5.0% (IQR, 2.5%-10.0%), whereas the median provider-level average number of vessels treated per patient was 1.20 (IQR, 1.13-1.31) and the median provider-level average number of treatments per patient was 1.38 (IQR, 1.26-1.63). Total annual reimbursement for each provider was directly correlated with new patient-procedure conversion rate (R2=0.47; P<0.001), mean number of vessels treated per patient (R2=0.31; P<0.001), and mean number of treatments per patient (R2=0.33; P<0.001). Conclusions A minority of providers perform most procedures and are reimbursed substantially more per procedure compared with most providers. Procedural conversion rate, number of vessels, and number of treatments per patient represent potential policy levers to curb overuse.

Tissue-engineered autologous grafts for facial bone reconstruction.

Facial deformities require precise reconstruction of the appearance and function of the original tissue. The current standard of care-the use of bone harvested from another region in the body-has major limitations, including pain and comorbidities associated with surgery. We have engineered one of the most geometrically complex facial bones by using autologous stromal/stem cells, native bovine bone matrix, and a perfusion bioreactor for the growth and transport of living grafts, without bone morphogenetic proteins. The ramus-condyle unit, the most eminent load-bearing bone in the skull, was reconstructed using an image-guided personalized approach in skeletally mature Yucatán minipigs (human-scale preclinical model). We used clinically approved decellularized bovine trabecular bone as a scaffolding material and crafted it into an anatomically correct shape using image-guided micromilling to fit the defect. Autologous adipose-derived stromal/stem cells were seeded into the scaffold and cultured in perfusion for 3 weeks in a specialized bioreactor to form immature bone tissue. Six months after implantation, the engineered grafts maintained their anatomical structure, integrated with native tissues, and generated greater volume of new bone and greater vascular infiltration than either nonseeded anatomical scaffolds or untreated defects. This translational study demonstrates feasibility of facial bone reconstruction using autologous, anatomically shaped, living grafts formed in vitro, and presents a platform for personalized bone tissue engineering.

Large, stratified, and mechanically functional human cartilage grown in vitro by mesenchymal condensation.

The efforts to grow mechanically functional cartilage from human mesenchymal stem cells have not been successful. We report that clinically sized pieces of human cartilage with physiologic stratification and biomechanics can be grown in vitro by recapitulating some aspects of the developmental process of mesenchymal condensation. By exposure to transforming growth factor-ß, mesenchymal stem cells were induced to condense into cellular bodies, undergo chondrogenic differentiation, and form cartilagenous tissue, in a process designed to mimic mesenchymal condensation leading into chondrogenesis. We discovered that the condensed mesenchymal cell bodies (CMBs) formed in vitro set an outer boundary after 5 d of culture, as indicated by the expression of mesenchymal condensation genes and deposition of tenascin. Before setting of boundaries, the CMBs could be fused into homogenous cellular aggregates giving rise to well-differentiated and mechanically functional cartilage. We used the mesenchymal condensation and fusion of CMBs to grow centimeter-sized, anatomically shaped pieces of human articular cartilage over 5 wk of culture. For the first time to our knowledge biomechanical properties of cartilage derived from human mesenchymal cells were comparable to native cartilage, with the Young's modulus of >800 kPa and equilibrium friction coeffcient of <0.3. We also demonstrate that CMBs have capability to form mechanically strong cartilage-cartilage interface in an in vitro cartilage defect model. The CMBs, which acted as "lego-like" blocks of neocartilage, were capable of assembling into human cartilage with physiologic-like structure and mechanical properties.