TROPIC: Transfascial Oblique Posterior Interbody Correction: Technical Note.

BACKGROUND: Adult spinal deformity (ASD) is a common problem in today's aging adult population, particularly in the thoracolumbar spine. This can lead to severe pain and disability, leading to poorer quality of life. Traditionally, open deformity correction has been the mainstay of treatment for these patients as it provides an excellent operative corridor; however, this comes with severe risk and high complication rates. There has been a trend towards more minimally invasive approaches to correct the deformity while persevering the muscle and soft tissue surrounding the bony spine across the fusion. METHODS: We describe a minimally invasive surgical technique through a Wiltse approach without invading the paraspinal musculature to gain access to the bony spine to perform lumbar interbody fusions and osteotomies. RESULTS: A total of 3 patients were identified for this technical note who underwent the TROPIC procedure for ASD. The patients had severe coronal and rotational imbalance. We were able to achieve adequate correction through an approach without disturbing the spinal musculature and soft tissues. CONCLUSIONS: This technique provides benefits of spinal rotational and coronal plane correction and restores lordosis with current advancements of today's technologies without the downsides of an open surgical approach.

Design thinking to improve healthcare delivery in the intensive care unit: Promise, pitfalls, and lessons learned.

Design thinking is a problem-solving approach characterized by the empathetic lens through which designers integrate perspectives of end-users and key stakeholders throughout the entire process of developing solutions. This approach is rooted in diverse fields including engineering, computer science, psychology, and business and is increasingly widespread in healthcare. Herein, we describe the promise of design thinking to help solve intractable problems in healthcare delivery, including those within the complex social and technical intensive care unit system. We highlight our team's experience using design thinking to address the complex problem of aligning the delivery of life-sustaining treatments with patients' individual goals, values, and preferences. However, given the high stakes of design failure in healthcare, we also discuss the limitations of this approach and the potential consequences of inadequate application. Finally, we suggest a pathway forward that combines the philosophy and tools of design thinking with existing methods within healthcare delivery science, such as qualitative research, quality improvement methods, and implementation science. Ultimately, we argue that design thinking is a valuable approach to guide designers, clinicians, researchers, and administrators towards a more genuine understanding of the healthcare experience, through the lens of patients, their families, and frontline clinicians.

Intraoperative ultrasound-assisted peripheral nerve surgery.

Historically, peripheral nerve surgery has relied on landmarks and fairly extensive dissection for localization of both normal and pathological anatomy. High-resolution ultrasonography is a radiation-free imaging modality that can be used to directly visualize peripheral nerves and their associated pathologies prior to making an incision. It therefore helps in localization of normal and pathological anatomy, which can minimize the need for extensive exposures. The authors found intraoperative ultrasound (US) to be most useful in the management of peripheral nerve tumors and neuromas of nerve branches that are particularly small or have a deep location. This study presents the use of intraoperative US in 5 cases in an effort to illustrate some of the applications of this useful surgical adjunct.

Surgical treatment of adult moyamoya disease with combined STA-MCA bypass and EDAS: demonstration of technique in video presentation.

The natural history of Moyamoya disease (MD) is variable. Moyamoya disease in children mostly presents with progressive ischemic complications and in adulthood it tends to present with hemorrhage. Surgical strategies depend on augmenting cerebral blood flow to the anterior cerebral circulation. Revascularization is the mainstay treatment for MD. We introduce a 31 year old female with a history of MD and leftsided revascularization as a child, who presented with headache, confusion, and worsening left sided weakness. Cranial computed tomography (CT) showed a right sided putaminal hemorrhage. Cerebral angiogram with selective external runs revealed MD, hypoplastic parietal branch of the superficial temporal artery (STA) on the right side and previous revascularization on the left side. Thus, our decision was made to perform a bypass with the frontal branch of the STA to an M3-M4 segment of the middle cerebral artery and an encephaloduroarteriomyosynangiosis with the parietal branch of the STA. The patient's postoperative course was uneventful. Postoperative CT angiogram confirmed patency of bypass. This technique provides immediate revascularization and seems to provide risk reduction for ischemic and hemorrhagic stroke. We review the natural history and surgical treatment of MD along with a case presentation in which surgical technique is demonstrated in video.

How I do it: treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery by extracranial-to-intracranial bypass and trapping.

BACKGROUND: Blood blister-like aneurysms (BBAs) pose a significant challenge to neurosurgeons and neuro-interventionalists. These fragile broad-based aneurysms have a propensity to rupture with minimal manipulation during surgical or endovascular explorations because, unlike saccular aneurysms, they lack all layers of the arterial wall. Aneurysm trapping with extracranial-intracranial (EC-IC) bypass is a safe and durable treatment for BBAs. METHODS: We describe our technique and the guiding principles for surgical bypass and trapping of BBAs of the supraclinoid internal carotid artery (ICA). CONCLUSIONS: Treatment of BBAs of the supraclinoid ICA remains difficult. Aneurysm trapping with EC-IC bypass treats BBAs definitively by eliminating the diseased segment of the ICA. We have found the technique and principles described here to be safe and durable in our hands.

Cerebral vasospasm.

Cerebral vasospasm causes delayed ischemic neurologic deficits after aneurysmal subarachnoid hemorrhage. This is a well-established clinical entity with significant associated morbidity and mortality. The underlying patholphysiology is highly complex and poorly understood. Large-vessel vasospasm, autoregulatory dysfunction, inflammation, genetic predispositions, microcirculatory failure, and spreading cortical depolarization are aspects of delayed neurologic deterioration that have been described in the literature. This article presents a perspective on cerebral vasospasm, as guided by the literature to date, specifically examining the mechanism, diagnosis, and treatment of cerebral vasospasm.

Demographic, circadian, and climatic factors in non-aneurysmal versus aneursymal subarachnoid hemorrhage.

BACKGROUND: Although, the relationship of spontaneous subarachnoid hemorrhage (SAH) to climatic or circadian factors has been widely studied, epidemiologic, circardian and climatic factors in non-aneurysmal SAH (naSAH), particularly perimesencephalic SAH (PMH), has not been reported before. OBJECTIVE: For the first time, demographic, climatic, and circadian variables are examined together as possible contributing factors comparing aSAH and naSAH. METHODS: We reviewed records for 384 patients admitted to University of Wisconsin Neurosurgery Service from January 2005 to December 2010 with spontaneous non-traumatic SAH. Patients were grouped as aSAH (n=338) or naSAH (n=46) on clinical and radiological criteria. PMH (n=32) was identified as a subgroup of naSAH based on radiological criteria. We logged demographic data, time of SAH, temperature at onset and atmospheric pressure at onset. The three subgroups were compared. RESULTS: Aneurysmal SAH occurred most often from 6am to 12pm (p<0.001); this correlation was not found in naSAH or PMH subgroups. Demographic analysis demonstrated predominance of female gender (p=0.008) and smoking (p=0.002) in aSAH, with predominance of hypercholesterolemia in naSAH (p=0.033). Atmospheric pressure, correlated with aSAH in the main county referral area, where we had detailed weather data (p<0.05); however, there was no weather correlation in the entire referral region taken together. Multivariate analysis supported a statistical difference only in smoking status between aSAH and naSAH groups (p=0.0159). CONCLUSION: Statistical differences in gender, smoking status, and history of hypercholesterolemia support a clinical distinction between aSAH and naSAH. Furthermore, circadian patterning of aSAH is not reproduced in naSAH, supporting pathophysiologic differences. Only smoking status provides a robust difference in aSAH and naSAH groups. Our data prompt further investigation into the relationship between aSAH and atmospheric pressure.

How reliable and accurate is indocyanine green video angiography in the evaluation of aneurysm obliteration?

INTRODUCTION: Indocyanine green video angiography (ICG-VA) has been recently introduced into neurovascular surgery and gained a role in assessing vessel patency and obliteration of intracranial aneurysms (IA) after clipping. Although its correlation with intra-postoperative angiography was demonstrated in previous studies, difficulties in evaluating aneurysm obliteration have not been reported. We report reliability and accuracy of ICG-VA in 109 clipped aneurysms with attention given to five cases in which ICG-VA evaluation resulted in false indication that aneurysms were secure in terms of complete obliteration. MATERIALS AND METHODS: A retrospective chart review was performed of IAs surgically treated by a single surgeon from January 2009. In all cases, aneurysm obliteration was confirmed by a combination of microdoppler ultrasonography (MUSG), ICG-VA, and post-operative angiography. RESULTS: ICG-VA appropriately assessed vessel patency and aneurysm obliteration in 93.5% of aneurysms clipped. In four cases (3.6%), puncturing the dome of the aneurysm after satisfactory clipping revealed persistent flow within the aneurysm despite ICG-VA showing no flow after clipping. In one case (0.9%), ICG-VA showed persistent flow within the aneurysm and MUSG did not, and puncture of the dome confirmed no flow within the aneurysm. In one case (0.9%), ICG-VA failed to demonstrate residual neck. CONCLUSION: ICG-VA is a simple and safe procedure and an important adjunct to microsurgical clipping of aneurysm. Although ICG-VA assesses vessel patency and obliteration of aneurysms in most cases, applying the principles of microsurgery in aneurysm clipping remains a main tool for obtaining the complete obliteration of aneurysm along with preservation of the normal vasculature.

Reliable time to estimate subglottal pressure.

Measuring subglottal pressure (P(s)) with complete interruption can be problematic due to unsteady plateaus in supraglottal pressure data traces during balloon valve interruption. Subjectively determining when the graph plateaus neglect the effects of laryngeal, auditory, and other physical reflexes may alter patient effort and glottal configuration. If the P(s) estimation was made at a consistent time before the onset of reflexes, the recorded pressure would not be dependent on subjective analysis by a clinician, and intrasubject data would be more precise. Previously collected data using the airflow interruption system have shown consistency at approximately 150 milliseconds after balloon valve inflation. To evaluate the validity of estimating P(s) at this point, a theoretical and a physical model were applied. A theoretical ideal gas model of capacitance calculated the time necessary for supraglottal pressure to equilibrate with P(s). Using a mechanical pseudolung which served as a constant pressure source, known subresistor pressures were compared to the pressure measured by the interruption device. Both models confirmed the validity of measuring P(s) consistently at 150 milliseconds into the 500-millisecond interruption. In human trials testing 25 subjects, mean intrasubject standard deviation using this optimal time constant was 0.66+/-0.37cm H(2)O, and 1.11+/-0.48cm H(2)O when performing plateau analysis (P<0.0005). This novel modification to the clinically feasible interruption model for P(s) estimation demonstrates a marked improvement in the reliability of balloon valve interruption while maintaining the validity demonstrated in previous studies.

The role of cation-dependent chloride transporters in neuropathic pain following spinal cord injury.

BACKGROUND: Altered Cl- homeostasis and GABAergic function are associated with nociceptive input hypersensitivity. This study investigated the role of two major intracellular Cl- regulatory proteins, Na+-K+-Cl- cotransporter 1 (NKCC1) and K+-Cl- cotransporter 2 (KCC2), in neuropathic pain following spinal cord injury (SCI). RESULTS: Sprague-Dawley rats underwent a contusive SCI at T9 using the MASCIS impactor. The rats developed hyperalgesia between days 21 and 42 post-SCI. Thermal hyperalgesia (TH) was determined by a decrease in hindpaw thermal withdrawal latency time (WLT) between days 21 and 42 post-SCI. Rats with TH were then treated with either vehicle (saline containing 0.25% NaOH) or NKCC1 inhibitor bumetanide (BU, 30 mg/kg, i.p.) in vehicle. TH was then re-measured at 1 h post-injection. Administration of BU significantly increased the mean WLT in rats (p < 0.05). The group administered with the vehicle alone showed no anti-hyperalgesic effects. Moreover, an increase in NKCC1 protein expression occurred in the lesion epicenter of the spinal cord during day 2-14 post-SCI and peaked on day 14 post-SCI (p < 0.05). Concurrently, a down-regulation of KCC2 protein was detected during day 2-14 post-SCI. The rats with TH exhibited a sustained loss of KCC2 protein during post-SCI days 21-42. No significant changes of these proteins were detected in the rostral region of the spinal cord. CONCLUSION: Taken together, expression of NKCC1 and KCC2 proteins was differentially altered following SCI. The anti-hyperalgesic effect of NKCC1 inhibition suggests that normal or elevated NKCC1 function and loss of KCC2 function play a role in the development and maintenance of SCI-induced neuropathic pain.

Estimating subglottal pressure via airflow redirection.

Subglottal pressure (SGP) is a valuable parameter in the research and clinical assessment of laryngeal function. The lungs serve as a constant pressure source during sustained phonation, and that pressure, SGP, can be used to determine the efficiency with which the larynx converts aerodynamic power to acoustic power. As the larynx serves as an aerodynamic transducer, the vocal efficiency (Ve) coefficient, defined as acoustic power (dB) divided by aerodynamic power (SGP x glottal airflow) has been shown to reliably reflect vocal health. However, current SGP measurement techniques are hesitantly used because of either an invasive nature or the requirement of intensive patient training. This study tests a novel device that has been designed to noninvasively estimate SGP through mechanical airflow redirection, producing a numeric output on completion of the trial, which lasts only a few seconds. The novelty of this design lies in the ease of use for both the patient and the clinician. Multiple mechanical airflow redirections occlude the airway for only 135 ms, which is predicted to limit the effect of confounding laryngeal reflexes that may occur during the trials. Additionally, the airflow redirection into a retention device allows for the pneumatic in-trial comparison of the estimated SGP with the pressure achieved by the patient, providing a numeric output to the clinician on completion.