Alfred Washington Adson: Perspectives on Intracranial Neurosurgery and the Responsibilities of the Neurosurgeon

In a period when the budding field of neurosurgery was believed to have little promise, Dr Alfred Washington Adson founded and led the first neurosurgical department at Mayo Clinic. He was not without reservations-surgical intervention for neurological conditions was rarely pursued because of poor outcomes and high complication rates, and Dr Adson acknowledged his early concerns about the future of neurosurgery in his memoirs. However, his education, mentorship, his training, and his first neurosurgical cases helped to shape the impact he ultimately had on the field and his legacy as a neurosurgeon. Dr Adson trained with several renowned Mayo general surgeons, notably his mentor Dr Emil Beckman, whose desire for operative precision shaped Dr Adson's drive to develop his own skills as a surgeon. Two years into his residency, he became the youngest staff surgeon and was tasked with managing the neurosurgical cases at Mayo. The five neurosurgical cases overseen by Dr Adson in the next year illuminated the opportunity for neurosurgery to drastically improve the lives of patients. Dr Adson, given the option of continuing as either a general surgeon or a neurosurgeon, ultimately chose to pursue neurosurgery. This article seeks to provide a historical perspective on the neurosurgeon Dr Alfred Washington Adson using primary and secondary accounts from the Mayo archives, highlighting his contributions to the early understanding of intracranial pathology and how his early experiences as a trainee developed into a personal passion for self-improvement, education, and advocacy for health care in America.

The association of thromboembolic complications and the use of tranexamic acid during resection of intracranial meningiomas: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Antifibrinolytics, such as tranexamic acid (TXA), have been shown to decrease intraoperative blood loss across multiple surgical disciplines. However, they carry the theoretical risk of thromboembolic events secondary to induced hypercoagulability. Therefore, the aim of this study was to systematically review the available literature and perform a meta-analysis on the use of TXA in meningioma resection to assess thromboembolic risks.

METHODS

The PubMed, Web of Science, and Google Scholar databases were reviewed for all randomized controlled trials presenting primary data on TXA use during resection of intracranial meningiomas. Data were gathered on operative duration, venous thromboembolic complications, deep venous thrombosis, use of allogeneic blood transfusion, estimated blood loss (EBL), and postoperative hemoglobin. Patients who received TXA were compared with controls who did not receive TXA intraoperatively using random-effects models.

RESULTS

A total of 508 unique articles were identified, of which 493 underwent full-text review. Ultimately, 6 studies with 381 total patients (190 receiving TXA) were included in the final analysis. All 6 trials were randomized, blinded, and placebo controlled with a TXA administration rate of a 20-mg/kg load followed by a 1-mg/kg/hr infusion. All studies were performed in lower-middle-income countries. There were no reported instances of venous thromboembolism (VTE) in the TXA and non-TXA cohorts. Patients receiving TXA exhibited fewer allogeneic transfusions (21.5% vs 41.6% [OR 0.26, 95% CI 0.09-0.77], p = 0.02) and lower EBL (MD -282.48 mL [95% CI -367.77 to -197.20 mL], p < 0.001) compared with patients who did not receive TXA, and they also had lower rates of perioperative complications (10.7% vs 19.9% [OR 0.47, 95% CI 0.2-0.95], p = 0.04).

CONCLUSIONS

Current literature suggests that TXA is not associated with increased risk for VTE when administered during resection of intracranial meningioma. TXA appears to decrease intraoperative blood loss and allogeneic transfusion requirements during meningioma resection and thus may improve the safety of surgical management of this pathology.

Flow diversion for basilar quadrifurcation aneurysms

BACKGROUND

Flow-diverting devices (FDDs), such as the Pipeline Embolization Device, have been gaining traction for treating challenging posterior circulation aneurysms. Few previous studies have focused on using FDDs to treat aneurysms of the basilar quadrifurcation.

METHODS

We retrospectively reviewed the use of FDDs to treat patients with basilar quadrifurcation aneurysms. Patients were assessed for aneurysm type, previous aneurysm treatment, technical success, periprocedural complications, and long-term aneurysm occlusion.

RESULTS

34 patients were assessed; aneurysms of the basilar apex (n=23) or superior cerebellar artery (SCA) (n=7), or both (n=1), and posterior cerebral artery (PCA) (n=3). The mean (SD) largest aneurysm dimension was 8.7 (6.1) mm (range 1.9-30.8 mm). 14 aneurysms were previously surgically clipped or endovascularly coiled. All aneurysms had a saccular morphology. Complete or near-complete occlusion was achieved in 30 of 34 patients (88%) at final angiographic follow-up, a mean (SD) of 6.6 (5.4) months (range 0-19 months) postoperatively. No patient experienced postoperative symptomatic occlusions of the SCA or PCA; 4 patients developed asymptomatic posterior communicating artery occlusions; 28 patients (82%) experienced no complications; whereas 3 (9%) experienced major complications and 3 (9%) experienced minor complications; and 1 patient died as a result of subarachnoid hemorrhage.

CONCLUSION

Flow diversion may be a safe and effective option to treat basilar quadrifurcation aneurysms. Previously treated basilar quadrifurcation aneurysms with recurrence or residual lesion may benefit from additional treatment with an FDD. Further prospective studies should be directed toward validating these findings.

A brief human history of ankylosing spondylitis: A scoping review of pathogenesis, diagnosis, and treatment

Background:

Ankylosing spondylitis (AS) is a chronic, progressive, inflammatory disease of the spine and SI joints. Diagnostic criteria and treatments have continued to evolve, necessitating a historical compendium of AS and its management. This paper aims to review the historical context underlying the discovery of AS, as well as the major diagnostic and therapeutic discoveries in the last two centuries.

Methods:

A scoping review of the literature pertaining to AS was performed via the Pubmed, Scopus, and Web of Science databases. Future directions of AS treatments were assessed by querying the clinicaltrials.gov website.

Results:

The history of AS can be traced as far back as ancient Egypt (as evidenced by the discovery of its presence in ancient Egyptian mummies) to the late 20^th century, when the inherited nature of AS was linked to a genetic factor, HLA-B27. Each discovery made throughout the years led to further investigations into the pathophysiology, diagnosis, and treatment of AS. The criteria to differentiate AS from rheumatoid arthritis were first reported in 1893. Since then, diagnostic criteria for AS have undergone a series of changes before the present-day diagnostic criteria for AS were ultimately determined in 2009 by the Assessment of Spondyloarthritis International Society.

Conclusion:

As the pathophysiology of AS is better understood, healthcare providers are able to diagnose and treat the condition more effectively. In particular, earlier diagnosis and multiple treatment options have facilitated efficient and more effective treatment.

The impact of different fat depots in the body on the progression of atrial fibrillation - data from RACE V

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation, Medtronic

Background

Paroxysmal atrial fibrillation (PAF) progression is associated with cardiovascular complications and worse outcome. Obesity is independently associated with AF prevalence and progression. The association between different fat depots in the body with AF is unclear.

Aim

We aim to systematically investigate the association of different fat depots in the body with AF.

Methods

417 patients with PAF and continuous rhythm monitoring (implantable loop recorder or pacemaker) were included in the prospective RACE V study. In addition to extensive phenotyping at baseline including calculating BMI and measuring waist circumference (WC) epicardial and pericardial fat were measured on non-contrast enhanced cardiac CT scans by tracing the pericardium manually on every slice and afterwards fat automatically summed between -50 and -150 HU. Epicardial fat was defined as fat within the pericardium, pericardial fat as fat inside the pericardium and adjacent to the pericardium and thoracic fat as adjacent fat outside the pericardium. AF progression was defined as (1) progression to persistent or permanent AF, or (2) progression of PAF with &gt;3% burden increase within 2.2years of follow-up. Multivariable logistic regression analysis was used to analyse the association of different fat pads with AF progression.

Results

Six percent of patients per year showed AF progression (51/417) after a median follow-up of 2.2 (1.6-2.8) years. Multivariate analysis identified WC (odds ratio [OR] 1.03, 95% confidence intervals [CI] 1.01-1.06, p=.014) to be associated with AF progression. Epicardial fat (OR 1.00, 95%CI .99-1.01, p=.407), pericardial fat (OR 1.00, 95%CI .99-1.01, p=.311), thoracic fat (OR 1.00, 95%CI .99-1.01, p=.372), and BMI (OR 1.03, 95%CI .97-1.10, p=.328) showed no relation with AF progression.

Conclusion

AF progression occurred in 6% per year in patients with PAF. In contrast to epicardial, pericardial and thoracic fat measured in a semiautomatic way, WC was the only fat depot associated with AF progression. Whether a more different assessment of obesity and epicardial fat may demonstrate an association with AF progression warrants further study.

Instability in a laser-diode-pumped microchip Nd:YAG laser in a n-ary product scheme

Dynamical instability, chaotic pulsations, and generalized bistability have been observed in a laser-diode-pumped microchip Nd:YAG laser operating in a double transition scheme in which lasing occurs on two transitions with overlapping gain profiles, F(3/2)(4)(2)? I(11/2)(4)(3) and F(3/2)(4)(1)? I(11/2)(4)(2), and simultaneously involves excited Nd atoms from different sublevels of the upper manifold. The modeling of the experimental results requires rate equations that include cross-gain coupling among oscillating modes that belong to different transitions whose population inversion densities are determined by the Boltzmann distribution.