Search

Background While open approaches have historically been used in the surgical treatment of intradural-extramedullary spine tumors, minimally-invasive surgical (MIS) techniques are frequently applied to minimize post-operative complications associated with open surgery. Tubular retractor systems in particular have been employed in combination with the unilateral hemilaminectomy (UHL) approach. Here we describe the use of a Williams retractor as a safe and effective minimally-invasive alternative to tubular retractor systems with similar post-operative outcomes. Methods We retrospectively reviewed a cohort of eight patients who underwent unilateral hemilaminectomy using a Williams retractor for the minimally-invasive resection of intradural-extramedullary neoplasms at a large tertiary academic center from 2017 to 2019. Patient demographics, pathologic specimens, radiographic studies, and intraoperative parameters were collected and analyzed. Results In our series, gross total resection was achieved in all cases. Average operative time was 158 ± 40 minutes, the mean estimated blood loss (EBL) was 44.4 ± 30.4 mL, and mean length of stay was three days. All patients reported symptomatic improvement at follow-up as reported by Visual Analog Scale scores. Conclusion A Williams retractor yields similar outcomes with respect to post-operative pain, operative time, and EBL as it maintains the advantages of the UHL approach in the resection of intradural-extramedullary spine tumors while enhancing feasibility and providing significant cost savings.

Wild-type transthyretin (ATTRwt) amyloid deposits have been found in the ligamentum flavum of patients undergoing surgery for spinal stenosis. The relationship between ATTRwt and ligamentum flavum thickness is unclear. We used pre-operative magnetic resonance imaging (MRI) to analyze ligamentum flavum thickness in lumbar spinal stenosis patients with and without ATTRwt amyloid.We retrospectively identified 178 patients who underwent lumbar spine surgery. Ligamentum flavum thickness of 253 specimens was measured on T2-weighted axial MRI. Amyloid presence was confirmed through Congo red staining of specimens, and ATTRwt was confirmed using mass-spectrometry and gene sequencing.Twenty four of the 178 patients (13.5%) were found to have ATTRwt in the ligamentum flavum. Forty ATTRwt specimens and 213 non-ATTRwt specimens were measured. Mean ligamentum flavum thickness was 4.92 (±1.27) mm in the ATTRwt group and 4.00 (±1.21) mm in the non-ATTRwt group (p 0.01). The ligamentum flavum was thickest at L4-L5, with a thickness of 5.15 (±1.27) mm and 4.23 (±1.29) mm in the ATTRwt and non-ATTRwt group, respectively (p = 0.007). There was a significant difference in ligamentum flavum thickness between ATTRwt and non-ATTRwt case for both patients younger than 70 years (p = 0.016) and those older than 70 years (p = 0.004). ATTRwt patients had greater ligamentum flavum thickness by 0.83 mm (95% confidence interval (CI): 0.41-1.25 mm, p 0.001) when controlled for age and lumbar level.Patients with ATTRwt had thicker ligamentum flavum compared to patients without ATTRwt. Further studies are needed to investigate the pathophysiology of ATTRwt in ligamentum flavum thickening.

Background Wild-type transthyretin amyloid (ATTRwt) has been noted to deposit in the ligamentum flavum of the spine. Prior studies have focused on ATTRwt in the lumbar region, but studies discussing its presence in other levels of the spine are lacking. We report on the presentation of patients with confirmed amyloid in the cervicothoracic regions and discuss the literature to date. Methods We retrospectively identified patients at a single institution who underwent surgery for spinal stenosis and had pathologic specimens sent for amyloidosis testing with Congo red staining. ATTRwt was confirmed by the presence of transthyretin amyloid by typing and the absence of mutations in the TTR gene sequence. A final study group of patients with ATTRwt and spinal involvement was established (n = 27). Results Of 27 patients with amyloid in the spine, 24 (89%) had amyloid present in the lumbar region, 2 (7%) had amyloid in the cervical region, and 1 (4%) had amyloid in the thoracic region. The median age at which patients in the study underwent surgery was 71 years (interquartile range: 9). Spinal stenosis was the indication for surgery in 26 of 27 (96%) patients. Surgery involved 1 or 2 spinal levels in 24 of 27 (89%) patients. Conclusions ATTRwt amyloid predominantly deposits in the lumbar region, but it can also be present in the cervical and thoracic regions. While the lumbar regions should remain a focus for evaluation of ATTRwt amyloidosis, the cervicothoracic region should not be ignored.

OBJECTIVE Spinal anesthesia (SA) is an alternative to general anesthesia (GA) for lumbar spine surgery, including complex instrumented fusion, although there are relatively few outcome data available. The authors discuss their experience using SA in a modern complex lumbar spine surgery practice to describe its utility and implementation. METHODS Data from patients receiving SA for lumbar spine surgery by one surgeon from March 2017 to December 2020 were collected via a retrospective chart review. Cases were divided into nonfusion and fusion procedure categories and analyzed for demographics and baseline medical status; pre-, intra-, and postoperative events; hospital course, including Acute Pain Service (APS) consults; and follow-up visit outcome data. RESULTS A total of 345 consecutive lumbar spine procedures were found, with 343 records complete for analysis, including 181 fusion and 162 nonfusion procedures and spinal levels from T11 through S1. The fusion group was significantly older (mean age 65.9 ± 12.4 vs 59.5 ± 15.4 years, p < 0.001) and had a significantly higher proportion of patients with American Society of Anesthesiologists (ASA) Physical Status Classification class III (p = 0.009) than the nonfusion group. There were no intraoperative conversions to GA, with infrequent need for a second dose of SA preoperatively (2.9%, 10/343) and rare preoperative conversion to GA (0.6%, 2/343) across fusion and nonfusion groups. Rates of complications during hospitalization were comparable to those seen in the literature. The APS was consulted for 2.9% (10/343) of procedures. An algorithm for the integration of SA into a lumbar spine surgery practice, from surgical and anesthetic perspectives, is also offered. CONCLUSIONS SA is a viable, safe, and effective option for lumbar spine surgery across a wide range of age and health statuses, particularly in older patients and those who want to avoid GA. The authors’ protocol, based in part on the largest set of data currently available describing complex instrumented fusion surgeries of the lumbar spine completed under SA, presents guidance and best practices to integrate SA into contemporary lumbar spine practices.

Wild-type transthyretin (ATTRwt) amyloid deposition has been found in the ligamentum flavum (LF) of patients undergoing spinal stenosis surgery. Our group previously reported that ATTRwt amyloid is associated with an increased lumbar ligamentum flavum thickness at symptomatic levels that required surgery. A comprehensive evaluation of LF thickness at asymptomatic levels in addition to symptomatic, treated levels has never been performed in ATTRwt patients. In this study, we compare the total LF thickness of all lumbar levels (lumbar LF burden) in ATTRwt and non-ATTRwt patients.We retrospectively identified 177 patients who underwent lumbar spine surgery. Ligamentum flavum thickness of 885 lumbar levels was measured on T2-weighted axial MRI. Amyloid presence was confirmed through Congo red staining of specimens, and subtype of ATTRwt was confirmed using mass-spectrometry and gene sequencing.Of the 177 patients, 30 (16.9%) were found to have ATTRwt in the ligamentum flavum. One hundred and fifty ATTRwt levels and 735 non-ATTRwt levels were measured by four different reviewers, with an intraclass coefficient (ICC) of 0.79. Mean ligamentum flavum thickness was 4.64 (±1.31) mm in the ATTRwt group and 3.99 (±1.45) mm in the non-ATTRwt group (p 0.001). The lumbar LF burden (sum of ligamentum flavum thickness at all lumbar levels) for ATTRwt patients was 23.22 (±4.48) mm, and for non-ATTRwt patients was 19.96 (±5.49) mm (p = 0.003) CONCLUSION: The lumbar LF burden is greater in patients with ATTRwt amyloid compared to non-ATTRwt patients. This supports prior evidence that ATTRwt amyloid deposition might be associated with increased LF thickness and lumbar stenosis. This potential association requires more research and could be an important finding, as medications have recently become available that can treat patients with ATTRwt amyloid deposition.

Background Transthyretin wild-type (ATTRwt) amyloidosis is a systemic process resulting in deposition of misfolded transthyretin protein in several different tissues throughout the body. It is known to be a cause of progressive, life-threatening cardiomyopathy and lumbar spinal stenosis and carpal tunnel syndrome. Case Description Here we present the case of a 71-year-old man who has clinical manifestations of all 3 entities over several years, providing a picture of the natural history of ATTRwt amyloidosis. This patient eventually underwent a heart transplant because of progressive cardiac amyloidosis (CA) resulting in end-stage heart failure. However, symptoms in carpal tunnel and lumbar spine manifested years before the symptoms of heart failure. ATTRwt amyloidosis may present as a clinical triad of lumbar stenosis, carpal tunnel syndrome, and heart failure. Recently developed medications have shown efficacy in slowing the progress of systemic and cardiac amyloidosis. Conclusions Knowing that extracardiac symptoms may occur first, we propose that sending ligamentum flavum and flexor tenosynovium for pathologic evaluation may be a unique opportunity to screen and treat a population of patients at risk for developing CA and heart failure.

Since antiquity, philosophers, theologians, and scientists have been interested in human memory. However, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, J Exp Psychol 113:1–2, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, Behav Brain Sci 24:87–185, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle What is working-memory capacity? 297–314, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison and Chein, Psychol Bull Rev 18:46–60 2011). However, initial investigations across a wide variety of cognitive functions have produced mixed results regarding the transferability of training-related improvements. Across two experiments, the present research focuses on the benefit of working memory training on visual short-term memory capacity—a cognitive process that has received little attention in the training literature. Data reveal training-related improvement of global measures of visual short-term memory as well as of measures of the independent sub-processes that contribute to capacity (Awh et al., Psychol Sci 18(7):622–628, 2007). These results suggest that the ability to inhibit irrelevant information within and between trials is enhanced via n-back training allowing for selective improvement on untrained tasks. Additionally, we highlight a potential limitation of the standard adaptive training procedure and propose a modified design to ensure variability in the training environment.