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Andrew Kai-Hong Chan, Winward Choy, Catherine A. Miller, Leslie C. Robinson and Praveen V. Mummaneni

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is associated with improved patient-reported outcomes in well-selected patients. Recently, some neurosurgeons have aimed to further improve outcomes by utilizing multimodal methods to avoid the use of general anesthesia. Here, the authors report on the use of a novel awake technique for MI-TLIF in two patients. They describe the successful use of liposomal bupivacaine in combination with a spinal anesthetic to allow for operative analgesia.

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Winward Choy, Won Kim, Daniel Nagasawa, Stephanie Stramotas, Andrew Yew, Quinton Gopen, Andrew T. Parsa and Isaac Yang

Meningiomas are mostly benign, slow-growing tumors of the CNS that originate from arachnoidal cap cells. While monosomy 22 is the most frequent genetic abnormality found in meningiomas, a multitude of other aberrant chromosomal alterations, signaling pathways, and growth factors have been implicated in its pathogenesis. Losses on 22q12.2, a region encoding the tumor suppressor gene merlin, represent the most common genetic alterations in early meningioma formation. Malignant meningioma progression, however, is associated with more complex karyotypes and greater genetic instability. Cytogenetic studies of atypical and anaplastic meningiomas revealed gains and losses on chromosomes 9, 10, 14, and 18, with amplifications on chromosome 17. However, the specific gene targets in a majority of these chromosomal abnormalities remain elusive.

Studies have also implicated a myriad of aberrant signaling pathways involved with meningioma tumorigenesis, including those involved with proliferation, angiogenesis, and autocrine loops. Understanding these disrupted pathways will aid in deciphering the relationship between various genetic changes and their downstream effects on meningioma pathogenesis.

Despite advancements in our understanding of meningioma pathogenesis, the conventional treatments, including surgery, radiotherapy, and stereotactic radiosurgery, have remained largely stagnant. Surgery and radiation therapy are curative in the majority of lesions, yet treatment remains challenging for meningiomas that are recurrent, aggressive, or refractory to conventional treatments. Future therapies will include combinations of targeted molecular agents as a result of continued progress in the understanding of genetic and biological changes associated with meningiomas.

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Michael M. Safaee, Alexander Tenorio, Joseph A. Osorio, Winward Choy, Dominic Amara, Lillian Lai, Annette M. Molinaro, Yalan Zhang, Serena S. Hu, Bobby Tay, Shane Burch, Sigurd H. Berven, Vedat Deviren, Sanjay S. Dhall, Dean Chou, Praveen V. Mummaneni, Charles M. Eichler, Christopher P. Ames and Aaron J. Clark


Anterior approaches to the lumbar spine provide wide exposure that facilitates placement of large grafts with high fusion rates. There are limited data on the effects of obesity on perioperative complications.


Data from consecutive patients undergoing anterior lumbar interbody fusion (ALIF) from 2007 to 2016 at a single academic center were analyzed. The primary outcome was any perioperative complication. Complications were divided into those occurring intraoperatively and those occurring postoperatively. Multivariate logistic regression was used to assess the association of obesity and other variables with these complications. An estimation table was used to identify a body mass index (BMI) threshold associated with increased risk of postoperative complication.


A total of 938 patients were identified, and the mean age was 57 years; 511 were females (54.5%). The mean BMI was 28.7 kg/m2, with 354 (37.7%) patients classified as obese (BMI ≥ 30 kg/m2). Forty patients (4.3%) underwent a lateral transthoracic approach, while the remaining 898 (95.7%) underwent a transabdominal retroperitoneal approach. Among patients undergoing transabdominal retroperitoneal ALIF, complication rates were higher for obese patients than for nonobese patients (37.0% vs 28.7%, p = 0.010), a difference that was driven primarily by postoperative complications (36.1% vs 26.0%, p = 0.001) rather than intraoperative complications (3.2% vs 4.3%, p = 0.416). Obese patients had higher rates of ileus (11.7% vs 7.2%, p = 0.020), wound complications (11.4% vs 3.4%, p < 0.001), and urinary tract infections (UTI) (5.0% vs 2.5%, p = 0.049). In a multivariate model, age, obesity, and number of ALIF levels fused were associated with an increased risk of postoperative complication. An estimation table including 19 candidate cut-points, odds ratios, and adjusted p values found a BMI ≥ 31 kg/m2 to have the highest association with postoperative complication (p = 0.012).


Obesity is associated with increased postoperative complications in ALIF, including ileus, wound complications, and UTI. ALIF is a safe and effective procedure. However, patients with a BMI ≥ 31 kg/m2 should be counseled on their increased risks and warrant careful preoperative medical optimization and close monitoring in the postoperative setting.