Kevin Carr

Extent of intraoperative muscle dissection does not affect long-term outcomes after minimally invasive surgery versus open-transforaminal lumbar interbody fusion surgery: A prospective longitudinal cohort study.

Background: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus open TLIF, addressing lumbar degenerative disc disease (DDD) or grade I spondylolisthesis (DS), are associated with shorter hospital stays, decreased blood loss, quicker return to work, and equivalent short- and long-term outcomes. However, no prospective study has assessed whether the extent of intraoperative muscle trauma utilizing creatinine phosphokinase levels (CPK) differently impacts long-term outcomes. Methods: Twenty-one patients underwent MIS-TLIF (n = 14) versus open-TLIF (n = 7) for DDD or DS. Serum CPK levels were measured at baseline, and postoperatively (days 1, 7, and 1.5, 3 and 6 months). The correlation between the extent of intraoperative muscle trauma and two-year improvement in functional disability was evaluated (multivariate regression analysis). Additionally, baseline and two-year changes in Visual Analog Scale (VAS)-leg pain (LP), VAS-back pain (BP), Oswestry Disability Index (ODI), Short-Form-36 (SF-36) Physical Component Score (PCS) and SF-36 Mental Component Score (MCS), and postoperative satisfaction with surgical care were assessed. Results: Although the mean change from baseline in the serum creatine phosphokinase level on POD 1 was greater for MIS-TLIF (628.07) versus open-TLF (291.42), this did not correlate with lesser two-year improvement in functional disability. Both cohorts also showed similar two-year improvement in VAS-LP, ODI, and SF-36 PCS/MCS. Conclusion: Increased intraoperative muscle trauma unexpectedly observed in higher postoperative CPK levels for MIS-TLIF versus open-TLIF did not correlate with any differences in two-year improvement in pain and functional disability.

Neurosurgical checklists: a review

Morbidity due to avoidable medical errors is a crippling reality intrinsic to health care. In particular, iatrogenic surgical errors lead to significant morbidity, decreased quality of life, and attendant costs. In recent decades there has been an increased focus on health care quality improvement, with a concomitant focus on mitigating avoidable medical errors. The most notable tool developed to this end is the surgical checklist. Checklists have been implemented in various operating rooms internationally, with overwhelmingly positive results. Comparatively, the field of neurosurgery has only minimally addressed the utility of checklists as a health care improvement measure. Literature on the use of checklists in this field has been sparse. Considering the widespread efficacy of this tool in other fields, the authors seek to raise neurosurgical awareness regarding checklists by reviewing the current literature.

The Incidence and Risk Factors of Associated Acute Myocardial Infarction (AMI) in Acute Cerebral Ischemic (ACI) Events in the United States

Objectives To determine the association between myocardial infarction (AMI) and clinical outcome in patients with primary admissions diagnosis of acute cerebral ischemia (ACI) in the US. Methods Data from Nationwide Inpatient Sample (NIS) was queried from 2002–2011 for inpatient admissions of patients with a primary diagnosis of ACI with and without AMI using International Classification of Diseases, Ninth Revision, Clinical Modification coding (ICD-9). A multivariate stepwise regression analysis was performed to assess the correlation between identifiable risk factors and clinical outcomes. Results During 10 years the NIS recorded 886,094 ACI admissions with 17,526 diagnoses of AMI (1.98%). The overall cumulative mortality of cohort was 5.65%. In-hospital mortality was associated with AMI (aOR 3.68; 95% CI 3.49–3.88, p≤0.0001), rTPA administration (aOR 2.39 CI, 2.11–2.71, p<0.0001), older age (aOR 1.03, 95% CI, 1.03–1.03, P<0.0001) and women (aOR 1.06, 95% CI 1.03–1.08, P<0.0001). Overall, mortality risk declined over the course of study; from 20.46% in 2002 to 11.8% in 2011 (OR 0.96, 95% CI 0.95–0.96, P<0.0001). Survival analysis demonstrated divergence between the AMI and non-AMI sub-groups over the course of study (log-rank p<0.0001). Conclusion Our study demonstrates that although the prevalence of AMI in patients hospitalized with primary diagnosis of ACI is low, it negatively impacts survival. Considering the high clinical burden of AMI on mortality of ACI patients, a high quality monitoring in the event of cardiac events should be maintained in this patient cohort. Whether prompt diagnosis and treatment of associated cardiovascular diseases may improve outcome, deserves further study.

Endoscopic removal of an intraventricular primitive neuroectodermal tumor: retrieval of a free-floating fragment using a urological basket retriever.

The endoscopic resection of intraventricular tumors represents a unique challenge to the neurological surgeon. These neoplasms are invested deep within the brain parenchyma and are situated among neurologically vital structures. Additionally, the cerebrospinal fluid system presents a dynamic pathway for resected tumors to be mobilized and entrapped in other regions of the brain. In 2011, the authors treated a 3-year-old girl with a third ventricular mass identified on stereotactic brain biopsy as a WHO Grade IV CNS primitive neuroectodermal tumor. After successful neoadjuvant chemotherapy, endoscopic resection was performed. Despite successful resection of the tumor, the operation was complicated by mobilization of the resected tumor and entrapment in the atrial horn of the lateral ventricle. Using a urological stone basket retriever, the authors were able to retrieve the intact tumor without additional complications. The flexibility afforded by the nitinol urological stone basket was useful in the endoscopic removal of a free-floating intraventricular tumor. This device may prove to be useful for other practitioners performing these complicated intraventricular resections.

Incidence and morbidity of craniocervical arterial dissections in atraumatic subarachnoid hemorrhage patients who underwent aneurysmal repair

Background No studies have assessed the incidence of craniocervical arterial dissections (CCADs) and its association to mortality in hospitalized patients with a primary diagnosis of atraumatic subarachnoid hemorrhage (SAH) requiring aneurysmal repair. We hypothesize that the incidence of CCADs in these patients has increased over time as well as its association to mortality. Methods We conducted a 9 year retrospective assessment of the incidence of CCADs in patients hospitalized with a primary diagnosis of an SAH requiring repair and the effect of CCAD on mortality. Using the Nationwide Inpatient Sample (NIS), we queried records from 2003 to 2011 for an ICD-9 (International Classification of Diseases-9) code corresponding to admissions for atraumatic SAH. Demographical data, incidence of CCADs, type of aneurysmal repair, length of hospital stay, and hospital mortality were recorded. Multivariate logistical regression models were fitted to assess for the impact of CCAD on inhospital mortality and morbidity. Results During the period 2003–2011, of the NIS reported 18 260 patients who required aneurysmal SAH repair, 9737 (53.32%) underwent endovascular coiling and 8523 (46.48%) had surgical clipping. There were 131 patients in the cohort with reported CCADs: 94 (71.75%) of these patients had received endovascular coiling repair and 37 (28.25%) had undergone surgical clipping repair. Patients who underwent endovascular coiling had a higher rate of CCADs in this cohort (OR 2.94; 95% CI 2.00 to 4.31, p<0.0001). The incidence of CCADs in this population increased by an average rate of 9.4% per year (OR 1.14; 95% CI 1.06 to 1.23, p<0.0006), from 0.49% in 2003 to 1.10% in 2011. The diagnosis of CCAD added 3 and 6 more days to median length of hospitalization stay for surgical clipping and endovascular coiling, respectively. The unadjusted rate of mortality was 8.4% in the CCADs subgroup, and the presence of CCAD was not a predictor of mortality in our multivariate regression model (OR 0.68; 95% CI 0.36 to 1.27, p=0.2244). Conclusions Our study indicates an annual increase in the incidence of CCADs in patients admitted with SAH who require aneurysmal repair. More than two-thirds of these patients that developed CCADs had undergone endovascular coiling repair. A diagnosis of CCAD increased the length of hospital stay but had no statistically significant association with mortality in this patient population.

Malignant stroke in a ticagrelor non-responder as a complication following aneurysm treatment with the Pipeline Embolization Device™

The Pipeline Embolization Device™ (PED; Covidien Neurovascular Inc, Irvine, CA, USA) is a flow-diverting stent often used for the endovascular treatment of large or giant, wide-necked intracranial aneurysms of the internal carotid artery. Because of the inherent thrombogenicity of intracranial stents, dual-antiplatelet therapy is initiated after placement, which has been shown to decrease morbidity and mortality related to perioperative ischemic events in neurointerventional procedures. However, in some series, as much as 50% of patients demonstrate clopidogrel non-responsiveness. In these non-responders, alternate agents such as ticagrelor can be used to achieve adequate anticoagulation. Compared with clopidogrel, a prodrug requiring Cytochrome P450 enzymolysis for activation, ticagrelor directly and reversibly inhibits the P2Y12 ADP receptor. The absorption of the prodrug and the formation of its active metabolite is comparatively quicker (tmax 1.3–2 hours; 1.5–3 hours, respectively). To date, there have been no documented cases of ticagrelor non-responsiveness involving patients undergoing placement of flow-diverting stents or other endovascular neuro-interventional procedures.

Posterior fossa syndrome with delayed MR evidence of unilateral superior cerebellar peduncle (SCP) damage

Posterior fossa syndrome (PFS) is a well-known sequela of midline posterior fossa tumor resection. Patients typically exhibit transient behavioral, motor, and oculomotor disturbances that resolve within a few weeks to several months after surgery. The underlying pathophysiology of PFS is not completely understood, but contemporary literature has implicated injury to the dentate nucleus and/or exiting dentatothalamocortical fiber bundles as a causative factor. The authors present a case of a young male who developed a delayed variant of PFS typified by motor deficits and demonstrated diffusion restriction in the ipsilateral superior cerebellar peduncle. Because the correlation between PFS and the superior cerebellar peduncle injury is poorly described in the literature, particularly with regard to relevant radiographic imaging, the authors of this report hope their findings will contribute to that insufficient body of evidence.