Thoracic Cage Deformity Correction in Patients with Lenke Type 1 Adolescent Idiopathic Scoliosis.

Whether the thoracic cage deformity in adolescent idiopathic scoliosis (AIS) can be sufficiently treated with vertebral derotation alone, has been quite controversial. Our aim is to control the hypothesis that the rib cage deformity (RCD) may be adequately corrected when only vertebral derotation is applied. We studied retrospectively patients treated for AIS with posterior spinal fusion without costoplasty. The RCD was assessed on lateral radiographs by rib index (RI). The correction of RI after surgery was calculated. Of the 103 patients that were finally included in our study, 29 patients (22 females and 7 males; mean age, 14.5 ± 2.1 years) represented Group A (Harrington rod instrumentation - no derotation), while 74 patients (61 females and 13 males; mean age, 14.1 ± 2.4 years) were operated with either a full pedicle screw system or a hybrid construct with hooks and pedicle screws (Group B-derotation). RI was significantly corrected after surgery in both groups. RI was significantly greater in Group A after surgery. Whatsoever, the correction of RI, thereby the RCD correction, did not significantly differ among groups. In conclusion, it cannot be suggested by the present study that vertebral derotation alone can offer an absolute correction of the deformity of the thoracic cage in patients with Lenke Type 1 AIS, and it seems also that the development of RCD may not exclusively result from the spinal deformity, thus questions can be further raised regarding scoliogeny per se.

Depth-Specific Hypoxic Responses to Spreading Depolarizations in Gyrencephalic Swine Cortex Unveiled by Photoacoustic Imaging.

Spreading depolarizations (SDs) are a marker of brain injury and have a causative effect on ischemic lesion progression. The hemodynamic responses elicited by SDs are contingent upon the metabolic integrity of the affected tissue, with vasoconstrictive reactions leading to pronounced hypoxia often indicating poor outcomes. The stratification of hemodynamic responses within different cortical layers remains poorly characterized. This pilot study sought to elucidate the depth-specific hemodynamic changes in response to SDs within the gray matter of the gyrencephalic swine brain. Employing a potassium chloride-induced SD model, we utilized multispectral photoacoustic imaging (PAI) to estimate regional cerebral oxygen saturation (rcSO2%) changes consequent to potassium chloride-induced SDs. Regions of interest were demarcated at three cortical depths covering up to 4 mm. Electrocorticography (ECoG) strips were placed to validate the presence of SDs. Through PAI, we detected 12 distinct rcSO2% responses, which corresponded with SDs detected in ECoG. Notably, a higher frequency of hypoxic responses was observed in the deeper cortical layers compared to superficial layers, where hyperoxic and mixed responses predominated (p < 0.001). This data provides novel insights into the differential oxygenation patterns across cortical layers in response to SDs, underlining the complexity of cerebral hemodynamics post-injury.