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Elias Atallah, Hassan Saad, Kimon Bekelis, Nohra Chalouhi, Stavropoula Tjoumakaris, David Hasan, Jorge Eller, David Stidd, Robert H. Rosenwasser and Pascal Jabbour

OBJECTIVE

Thromboembolic complications continue to be encountered with Pipeline embolization devices (PEDs) despite routine clopidogrel/aspirin antiplatelet therapy. This study examined the safety and efficacy of prasugrel in the management of clopidogrel-resistant patients treated for cerebral aneurysms.

METHODS

Four hundred thirty-seven consecutive patients were identified between January 2011 and May 2016. Patients allergic, or having less than 30% platelet inhibition, to a daily 75-mg dose of clopidogrel received 10 mg of prasugrel daily (n = 20) or 90 mg of ticagrelor twice daily (n = 2). The mean (± SD) follow-up duration was 15.8 ± 12.4 months. The primary outcome was the modified Rankin Scale (mRS) score registered before discharge and at each follow-up visit. To control confounding, multivariable mixed-effects logistic regression and propensity score conditioning were used.

RESULTS

Twenty-six (5.9%) of 437 patients presented with a subarachnoid hemorrhage (SAH). The mean patient age was 56.3 years, and 62 were women (14.2%). One of the 7 patients lost to follow-up received prasugrel. One patient was allergic to clopidogrel and prasugrel simultaneously. All patients receiving prasugrel or ticagrelor (n = 22) had an mRS score ≤ 2 on their latest follow-up visit (mean score 0.67 ± 1.15). In a multivariate analysis, clopidogrel did not affect the mRS score on last follow-up (p = 0.14). Multivariable logistic regression showed that clopidogrel was not associated with an increased long-term recurrence rate (OR 0.17, 95% CI 0.01–2.70, p = 0.21), an increased thromboembolic complication rate (OR 0.46, 95% CI 0.12–1.67, p = 0.24), or an increased hemorrhagic event rate (OR 0.39, 95% CI 0.91–1.64, p = 0.20). None of the patients receiving prasugrel or ticagrelor died or suffered a long-term recurrence or a hemorrhagic event; only 1 patient suffered from mild aphasia subsequent to a thromboembolic event. Three patients taking clopidogrel died during the study: 2 from acute SAH and 1 from intraparenchymal hemorrhage. Clopidogrel was not associated with an increased mortality rate (OR 2.18, 95% CI 0.11–43.27, p = 0.61). The same associations were present in propensity score–adjusted models.

CONCLUSIONS

In a cohort of patients treated with PEDs, prasugrel (10 mg/day) was a safe alternative to clopidogrel-resistant or clopidogrel-allergic patients, or nonresponders.

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Kimon Bekelis, Symeon Missios, Shannon Coy and Jeremiah N. Johnson

OBJECTIVE

The accuracy of public reporting in health care, especially from private vendors, remains an issue of debate. The authors investigated the association of the publicly reported physician complication rates in an online platform with real-world adverse outcomes of the same physicians for patients undergoing posterior lumbar fusion.

METHODS

The authors performed a cohort study involving physicians performing posterior lumbar fusions between 2009 and 2013 who were registered in the Statewide Planning and Research Cooperative System database. This cohort was merged with publicly available data over the same time period from ProPublica, a private company. Mixed-effects multivariable regression models were used to investigate the association of publicly available complication rates with the rate of discharge to a rehabilitation facility, length of stay, mortality, and hospitalization charges for the same surgeons.

RESULTS

During the selected study period, there were 8,457 patients in New York State who underwent posterior lumbar fusion performed by the 56 surgeons represented in the ProPublica Surgeon Scorecard over the same time period. Using a mixed-effects multivariable regression model, the authors demonstrated that publicly reported physician-level complication rates were not associated with the rate of discharge to a rehabilitation facility (OR 0.97, 95% CI 0.72–1.31), length of stay (adjusted difference −0.1, 95% CI −0.5 to 0.2), mortality (OR 0.87, 95% CI 0.49–1.55), and hospitalization charges (adjusted difference $18,735, 95% CI −$59,177 to $96,647). Similarly, no association was observed when utilizing propensity score–adjusted models, and when restricting the cohort to a predefined subgroup of Medicare patients.

CONCLUSIONS

After merging a comprehensive all-payer posterior lumbar fusion cohort in New York State with data from the ProPublica Surgeon Scorecard over the same time period, the authors observed no association of publicly available physician complication rates with objective outcomes.

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Kimon Bekelis, Daniel J. Gottlieb, Yin Su, A. James O'Malley, Nicos Labropoulos, Philip Goodney, Michael T. Lawton and Todd A. MacKenzie

OBJECTIVE

The comparative effectiveness of the 2 treatment options—surgical clipping and endovascular coiling—for unruptured cerebral aneurysms remains an issue of debate and has not been studied in clinical trials. The authors investigated the association between treatment method for unruptured cerebral aneurysms and outcomes in elderly patients.

METHODS

The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who had treatment for unruptured cerebral aneurysms between 2007 and 2012. To control for measured confounding, the authors used propensity score conditioning and inverse probability weighting with mixed effects to account for clustering at the level of the hospital referral region (HRR). An instrumental variable (regional rates of coiling) analysis was used to control for unmeasured confounding and to create pseudo-randomization on the treatment method.

RESULTS

During the study period, 8705 patients underwent treatment for unruptured cerebral aneurysms and met the study inclusion criteria. Of these patients, 2585 (29.7%) had surgical clipping and 6120 (70.3%) had endovascular coiling. Instrumental variable analysis demonstrated no difference between coiling and clipping in 1-year postoperative mortality (OR 1.25, 95% CI 0.68–2.31) or 90-day readmission rate (OR 1.04, 95% CI 0.66–1.62). However, clipping was associated with a greater likelihood of discharge to rehabilitation (OR 6.39, 95% CI 3.85–10.59) and 3.6 days longer length of stay (LOS; 95% CI 2.90–4.71). The same associations were present in propensity score–adjusted and inverse probability–weighted models.

CONCLUSIONS

In a cohort of Medicare patients, there was no difference in mortality and the readmission rate between clipping and coiling of unruptured cerebral aneurysms. Clipping was associated with a higher rate of discharge to a rehabilitation facility and a longer LOS.

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Kimon Bekelis, Daniel J. Gottlieb, Yin Su, Giuseppe Lanzino, Michael T. Lawton and Todd A. MacKenzie

OBJECTIVE

The impact of treatment method—surgical clipping or endovascular coiling—on the cost of care for patients with aneurysmal subarachnoid hemorrhage (SAH) is debated. Here, the authors investigated the association between treatment method and long-term Medicare expenditures in elderly patients with aneurysmal SAH.

METHODS

The authors performed a cohort study of 100% of the Medicare fee-for-service claims data for elderly patients who had undergone treatment for ruptured cerebral aneurysms in the period from 2007 to 2012. To control for measured confounding, the authors used propensity score–adjusted multivariable regression analysis with mixed effects to account for clustering at the hospital referral region (HRR) level. An instrumental variable (regional rates of coiling) analysis was used to control for unmeasured confounding by creating pseudo-randomization on the treatment method.

RESULTS

During the study period, 3210 patients underwent treatment for ruptured cerebral aneurysms and met the inclusion criteria. Of these patients, 1206 (37.6%) had surgical clipping and 2004 (62.4%) had endovascular coiling. The median total Medicare expenditures in the 1st year after admission for SAH were $113,000 (IQR $77,500–$182,000) for surgical clipping and $103,000 (IQR $72,900–$159,000) for endovascular coiling. When the authors adjusted for unmeasured confounders by using an instrumental variable analysis, clipping was associated with increased 1-year Medicare expenditures by $19,577 (95% CI $4492–$34,663).

CONCLUSIONS

In a cohort of Medicare patients with aneurysmal SAH, after controlling for unmeasured confounding, surgical clipping was associated with increased 1-year expenditures in comparison with endovascular coiling.

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Symeon Missios and Kimon Bekelis

OBJECTIVE

Fragmentation of care has been recognized as a major contributor to 30-day readmissions after surgical procedures. The authors investigated the association of evaluation in the hospital where the original procedure was performed with the rate of 30-day readmissions for patients presenting to the emergency department (ED) after craniotomy for primary brain tumor resection.

METHODS

A cohort study was conducted, involving patients who were evaluated in the ED within 30 days after discharge following a craniotomy for primary brain tumor resection between 2009 and 2013, and who were registered in the Statewide Planning and Research Cooperative System (SPARCS) database of New York State. A propensity score–adjusted model was used to control for confounding, whereas a mixed-effects model accounted for clustering at the hospital level.

RESULTS

Of the 610 patients presenting to the ED, 422 (69.2%) were evaluated in a hospital different from the one where the original procedure was performed (28.9% were readmitted), and 188 (30.8%) were evaluated at the original hospital (20.3% were readmitted). In a multivariable analysis, the authors demonstrated that being evaluated in the ED of the original hospital was associated with a decreased rate of 30-day readmission (OR 0.64, 95% CI 0.41–0.98). Similar associations were found in a mixed-effects logistic regression model (OR 0.63, 95% CI 0.40–0.96) and a propensity score–adjusted model (OR 0.64, 95% CI 0.41–0.98). This corresponds to one less readmission per 12 patients evaluated in the hospital where the original procedure was performed.

CONCLUSIONS

Using a comprehensive all-payer cohort of patients in New York State who were evaluated in the ED after craniotomy for primary brain tumor resection, the authors identified an association of assessment in the hospital where the original procedure was performed with a lower rate of 30-day readmissions. This underscores the potential importance of continuity of care in readmission prevention for these patients.

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Kimon Bekelis, Dan Gottlieb, Nicos Labropoulos, Yin Su, Stavropoula Tjoumakaris, Pascal Jabbour and Todd A. MacKenzie

OBJECTIVE

The impact of combined practices on the outcomes of unruptured cerebral aneurysm coiling remains an issue of debate. The authors investigated the association of combined open and endovascular expertise with the outcomes of unruptured cerebral aneurysm coiling.

METHODS

The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who underwent endovascular coiling for unruptured cerebral aneurysms between 2007 and 2012. To control for confounding, the authors used propensity score conditioning, with mixed effects to account for clustering at the hospital referral region level.

RESULTS

During the study period, there were 11,716 patients who underwent endovascular coiling for unruptured cerebral aneurysms and met the inclusion criteria. Of these, 1186 (10.1%) underwent treatment performed by hybrid neurosurgeons, and 10,530 (89.9%) by proceduralists who performed only endovascular coiling. Multivariable regression analysis with propensity score adjustment demonstrated a lack of association of combined practice with 1-year postoperative mortality (OR 0.84; 95% CI 0.58–1.23), discharge to rehabilitation (OR 1.0; 95% CI 0.66–1.51), 30-day readmission rate (OR 1.07; 95% CI 0.83–1.38), and length of stay (adjusted difference, 0.41; 95% CI −0.26 to 1.09). Higher procedural volume was independently associated with improved outcomes.

CONCLUSIONS

In a cohort of Medicare patients, the authors did not demonstrate a difference in mortality, discharge to rehabilitation, readmission rate, and LOS between hybrid neurosurgeons and proceduralists performing only endovascular coiling.

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Kimon Bekelis, Joanna S. Kerley-Hamilton, Amy Teegarden, Craig R. Tomlinson, Rachael Kuintzle, Nathan Simmons, Robert J. Singer, David W. Roberts, Manolis Kellis and David A. Hendrix

OBJECTIVE

The molecular mechanisms behind cerebral aneurysm formation and rupture remain poorly understood. In the past decade, microRNAs (miRNAs) have been shown to be key regulators in a host of biological processes. They are noncoding RNA molecules, approximately 21 nucleotides long, that posttranscriptionally inhibit mRNAs by attenuating protein translation and promoting mRNA degradation. The miRNA and mRNA interactions and expression levels in cerebral aneurysm tissue from human subjects were profiled.

METHODS

A prospective case-control study was performed on human subjects to characterize the differential expression of mRNA and miRNA in unruptured cerebral aneurysms in comparison with control tissue (healthy superficial temporal arteries [STA]). Ion Torrent was used for deep RNA sequencing. Affymetrix miRNA microarrays were used to analyze miRNA expression, whereas NanoString nCounter technology was used for validation of the identified targets.

RESULTS

Overall, 7 unruptured cerebral aneurysm and 10 STA specimens were collected. Several differentially expressed genes were identified in aneurysm tissue, with MMP-13 (fold change 7.21) and various collagen genes (COL1A1, COL5A1, COL5A2) being among the most upregulated. In addition, multiple miRNAs were significantly differentially expressed, with miR-21 (fold change 16.97) being the most upregulated, and miR-143–5p (fold change −11.14) being the most downregulated. From these, miR-21, miR-143, and miR-145 had several significantly anticorrelated target genes in the cohort that are associated with smooth muscle cell function, extracellular matrix remodeling, inflammation signaling, and lipid accumulation. All these processes are crucial to the pathophysiology of cerebral aneurysms.

CONCLUSIONS

This analysis identified differentially expressed genes and miRNAs in unruptured human cerebral aneurysms, suggesting the possibility of a role for miRNAs in aneurysm formation. Further investigation for their importance as therapeutic targets is needed.

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Kimon Bekelis, Ian D. Connolly, Huy M. Do and Omar Choudhri

OBJECTIVE

The impact of procedural volume on the outcomes of cerebrovascular surgery in children has not been determined. In this study, the authors investigated the association of operative volume on the outcomes of cerebrovascular neurosurgery in pediatric patients.

METHODS

The authors performed a cohort study of all pediatric patients who underwent a cerebrovascular procedure between 2003 and 2012 and were registered in the Kids' Inpatient Database (KID). To control for confounding, the authors used multivariable regression models, propensity-score conditioning, and mixed-effects analysis to account for clustering at the hospital level.

RESULTS

During the study period, 1875 pediatric patients in the KID underwent cerebrovascular neurosurgery and met the inclusion criteria for the study; 204 patients (10.9%) underwent aneurysm clipping, 446 (23.8%) underwent coil insertion for an aneurysm, 827 (44.1%) underwent craniotomy for arteriovenous malformation resection, and 398 (21.2%) underwent bypass surgery for moyamoya disease. Mixed-effects multivariable regression analysis revealed that higher procedural volume was associated with fewer inpatient deaths (OR 0.58; 95% CI 0.40–0.85), a lower rate of discharges to a facility (OR 0.87; 95% CI 0.82–0.92), and shorter length of stay (adjusted difference −0.22; 95% CI −0.32 to −0.12). The results in propensity-adjusted multivariable models were robust.

CONCLUSIONS

In a national all-payer cohort of pediatric patients who underwent a cerebrovascular procedure, the authors found that higher procedural volume was associated with fewer deaths, a lower rate of discharges to a facility, and decreased lengths of stay. Regionalization initiatives should include directing children with such rare pathologies to a center of excellence.

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Symeon Missios and Kimon Bekelis

OBJECTIVE

The accuracy of public reporting in health care is an issue of debate. The authors investigated the association of patient satisfaction measures from a public reporting platform with objective outcomes for patients undergoing spine surgery.

METHODS

The authors performed a cohort study involving patients undergoing elective spine surgery from 2009 to 2013 who were registered in the New York Statewide Planning and Research Cooperative System database. This cohort was merged with publicly available data from the Centers for Medicare and Medicaid Services (CMS) Hospital Compare website. A mixed-effects regression analysis, controlling for clustering at the hospital level, was used to investigate the association of patient satisfaction metrics with outcomes.

RESULTS

During the study period, 160,235 patients underwent spine surgery. Using a mixed-effects multivariable regression analysis, the authors demonstrated that undergoing elective spine surgery in hospitals with a higher percentage of patient-assigned high satisfaction scores was not associated with a decreased rate of discharge to rehabilitation (OR 0.77, 95% CI 0.57–1.06), mortality (OR 0.96, 95% CI 0.90–1.01), or hospitalization charges (β 0.04, 95% CI −0.16 to 0.23). However, it was associated with decreased length of stay (LOS; β −0.19, 95% CI −0.33 to −0.05). Similar associations were identified for hospitals with a higher percentage of patients who claimed they would recommend these institutions to others.

CONCLUSIONS

Merging a comprehensive all-payer cohort of spine surgery patients in New York state with data from the CMS Hospital Compare website, the authors were not able to demonstrate an association of improved performance in patient satisfaction measures with decreased mortality, rate of discharge to rehabilitation, and hospitalization charges. Increased patient satisfaction was associated with decreased LOS.