Hyponatremia is often seen after transsphenoidal surgery and is a source of considerable economic burden and patient-related morbidity and mortality. We performed a retrospective review of 344 patients who underwent transsphenoidal surgery at our institution between 2006 and 2012. Postoperative hyponatremia was seen in 18.0% of patients at a mean of 3.9 days postoperatively. Hyponatremia was most commonly mild (51.6%) and clinically asymptomatic (93.8%). SIADH was the primary cause of hyponatremia in the majority of cases (n = 44, 71.0%), followed by cerebral salt wasting (n = 15, 24.2%) and desmopressin over-administration (n = 3, 4.8%). The incidence of postoperative hyponatremia was significantly higher in patients with cardiac, renal and/or thyroid disease (p = 0.0034, Objective Risk (OR) = 2.60) and in female patients (p = 0.011, OR = 2.18) or patients undergoing post-operative cerebrospinal fluid drainage (p = 0.0006). Treatment with hypertonic saline (OR = −2.4, p = 0.10) and sodium chloride tablets (OR = −1.57, p = 0.45) was associated with a non-significant trend toward faster resolution of hyponatremia. The use of fluid restriction and diuretics should be de-emphasized in the treatment of post-transsphenoidal hyponatremia, as they have not been shown to significantly alter the time-course to the restoration of sodium balance.

Spinal epidural hematoma (SEH) occurring after chiropractic spinal manipulation therapy (CSMT) is a rare clinical phenomenon. Our case is unique because the patient had an undiagnosed cervical spinal arteriovenous malformation (AVM) discovered on pathological analysis of the evacuated hematoma. Although the spinal manipulation likely contributed to the rupture of the AVM, there was no radiographic evidence of the use of excessive force, which was seen in another reported case. As such, patients with a known AVM who have not undergone surgical intervention should be cautioned against symptomatic treatment with CSMT, even if performed properly. Regardless of etiology, SEH is a surgical emergency and its favorable neurological recovery correlates inversely with time to surgical evacuation.

Background: A minimally invasive approach to the L2-S1 disc spaces through a single, left-sided, retroperitoneal oblique corridor has been previously described. However, the size of this corridor varies, limiting access to the disc space in certain patients. Here, the authors retrospectively reviewed lumbar spine magnetic resonance imaging (MRI) in 300 patients to better define the size and variability of the retroperitoneal oblique corridor. Methods: Lumbar spine MRI from 300 patients was reviewed. The size of the retroperitoneal oblique corridor from L2-S1 was measured. It was defined as the (1) distance between the medial aspect of the aorta and the lateral aspect of the psoas muscle from L2-L5 and (2) the distance between the midpoint of the L5-S1 disc and the medial aspect of the nearest major vessel on the left at L5-S1. In addition, the rostral-caudal location of the iliac bifurcation was measured. Results: The size of the retroperitoneal oblique corridor at L2/3, L3/4, L4/5, and L5/S1 was, respectively, 17.3 ± 6.4 mm, 16.2 ± 6.3 mm, 14.8 ± 7.8 cm, and 13.0 ± 8.3 mm. The incidence of corridor size <1 cm at L2/3, L3/4, L4/5, and L5/S1 was 10.3%, 16.0%, 30.0%, and 39.3%, respectively. The iliac bifurcation was most commonly found behind the L4 vertebral body (n = 158, 52.67%) followed by the L4/5 disc space (n = 74, 24.67%). Conclusion: The size of the retroperitoneal oblique corridor diminishes in a rostral-caudal direction, often limiting access to the L4/5 and L5/S1 disc spaces.

Autogenous iliac crest bone marrow aspirate (BMA) has been shown to be a safe osteobiological adjunct to anterior cervical discectomy and fusion (ACDF), but little evidence exists to support its superiority to traditional methods. The object of this study was to retrospectively evaluate two cohorts of patients undergoing ACDF – with or without the use of BMA – in an effort to better characterize the clinical and radiographic outcomes associated with the use of BMA in ACDF. The charts of all patients undergoing ACDF with a collagen-hydroxyapatite (CHA) sponge, local vertebral autograft and a polyetheretherketone (PEEK) interbody graft with or without BMA by a single staff neurosurgeon between 2011 and 2016 were retrospectively reviewed. Post-operative dynamic plain films and CT scans for each patient were reviewed and each instrumented level was independently evaluated for fusion over time. A total of 203 cervical levels were instrumented in 92 patients (with BMA, 52 patients, 122 levels; without BMA, 40 patients, 81 levels). The mean radiographic follow-up period was 21.4 ± 18.4 months, over which time 154 of 203 (75.6%) instrumented cervical levels were found to have fused (BMA group, 93/122 segments fused [76.2%]; non-BMA group, 61/81 segments fused [75.3%], p = 1). Kaplan-Meier survival analysis demonstrated a higher probability of fusion at any given time point for the BMA group when compared with the non-BMA group (p < 0.001, log-rank test). BMA is a readily accessible, low-cost adjunct to ACDF that enhances the fusion rates seen with a CHA/PEEK allograft combination.