Evaluating the Healing Potential of J-Plasma Scalpel-Created Surgical Incisions in Porcine and Rat Models.

Cold atmospheric plasma devices generate reactive oxygen and nitrogen species that can be anti-microbial but also promote cell migration, differentiation, and tissue wound healing. This report investigates the healing of surgical incisions created using cold plasma generated by the J-Plasma scalpel (Precise Open handpiece, Apyx Medical, Inc.) compared to a steel scalpel in in vivo porcine and rat models. The J-Plasma scalpel is currently FDA approved for the delivery of helium plasma to cut, coagulate, and ablate soft tissue during surgical procedures. To our knowledge, this device has not been studied in creating surgical incisions but only during deeper dissection and hemostasis. External macroscopic and histologic grading by blinded reviewers revealed no significant difference in wound healing appearance or physiology in incisions created using the plasma scalpel as compared with a steel blade scalpel. Incisions created with the plasma scalpel also had superior hemostasis and a reduction in tissue and blood carryover. Scanning electron microscopy (SEM) and histology showed collagen fibril fusion occurred as the plasma scalpel incised through the tissue, contributing to a sealing effect. In addition, when bacteria were injected into the dermis before incision, the plasma scalpel disrupted the bacterial membrane as visualized in SEM images. External macroscopic and histologic grading by blinded reviewers revealed no significant difference in wound healing appearance or physiology. Based on these results, we propose additional studies to clinically evaluate the use of cold plasma in applications requiring hemostasis or when an increased likelihood of subdermal pathogen leakage could cause surgical site infection (i.e., sites with increased hair follicles).

Intraocular lens tilt due to optic-haptic junction distortion following intrascleral haptic fixation with the Yamane technique.

Purpose: To report two patients with a complication of Yamane intrascleral haptic fixation surgery (ISHF) with the Zeiss CT Lucia 602 lens: severely tilted intraocular lens (IOL) leading to significantly decreased vision in the early post-operative period. Observations: We report two patients presenting with severely tilted IOL implants one day and one month following Yamane ISHF. The first patient is a monocular 81-year-old woman referred for treatment of cornea edema. Initial surgery involved replacement of an anterior chamber lens with a CT Lucia 602 posterior chamber lens using Yamane technique and Descemet's stripping endothelial keratoplasty. The patient returned at one month follow-up with poor vision and IOL tilt observable at the slit lamp through a peripheral iridectomy site. Explanation of the Zeiss lens revealed haptic distortion at the optic-haptic insertion point such that each haptic was about 45° off axis to the plane of the optic in approximately equal and opposite directions. The second patient, a 75-year-old woman, was referred with a completely dislocated lens-bag complex in the right eye. The initial operative treatment for this patient included pars plana vitrectomy, retrieval and removal of the dislocated lens-bag complex, and placement of a Zeiss 602 lens via Yamane ISHF technique. On the first postoperative day, the patient was count fingers in the right eye with an intraocular pressure of 5 mm Hg and obvious IOL tilt on slit lamp examination. Explanation of the lens revealed severely distorted haptics relative to the optic by more than a 60-degree angle on both sides. In both cases, initial surgery was performed with an IOL inspected prior to implantation and found to have normal appearing haptics. At the end of each case, there was adequate centration and no tilt of the IOL. Management in both patients included removal of the defective lens and placement of a new, same power CT Lucia 602 lens via the Yamane technique. Visual acuity improved from CF to 20/30 best corrected after reoperation in both cases. Conclusions and importance: In summary, we describe a complication of Yamane ISHF with the CT Lucia 602 lens in which there is lens tilting associated with distortion at the optic-haptic fastening zone in the early postoperative period. In the event of a titled lens following Yamane ISHF, awareness of this complication may help surgeons consider lens replacement, as the haptics may be permanently distorted or damaged.

Corneal edema associated with degenerating Soemmering ring cataract: Clinical-pathologic correlation.

Purpose: To report three patients with an uncommon delayed complication of cataract extraction: corneal edema following dispersion of calcific lens particles from a degenerating Soemmering ring cataract. Observations: We report three patients, 75-92 years old, presenting with corneal edema and dispersed, degenerated calcific lens material in the anterior chamber and vitreous 20-30 years after cataract surgery. In all patients, calcific particles studded the posterior surface of the cornea in a gravity-dependent distribution without apparent inflammation and were associated with localized corneal edema. In one patient, calcific particles were also associated with secondary open angle glaucoma. Deposits originated from the calcified Soemmering ring cataract. Histopathological examination demonstrated extracellular calcific deposits compatible with cataractous lens material on the posterior surface of stripped Descemet membrane of two patients. The deposits were associated with prominent localized loss of corneal endothelium and were not associated with inflammation. Morphologically similar acellular material was identified in the biopsied aqueous and vitreous fluid of one patient. Management included endothelial keratoplasty, anterior chamber lavage, pars plana vitrectomy, aspiration/removal of a portion of Soemmering ring cataract without intraocular lens implant explantation, and the removal of the entire capsular bag/implant complex. Cornea cleared and visual acuity improved in both patients who underwent endothelial keratoplasty. Persistent elevated intraocular pressure led to visual deterioration in one patient with secondary glaucoma. Conclusions and Importance: Dispersion of calcific Soemmering ring cataract can occur decades following cataract surgery leading to corneal edema, secondary glaucoma, and vitreous opacities. Timely recognition of this phenomenon may prevent ocular morbidity, including corneal edema and glaucoma.

A Short-Term Assessment of Lumbar Sagittal Alignment Parameters in Patients Undergoing Anterior Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To determine if intraoperative on-table lumbar lordosis (LL) and segmental lordosis (SL) coincide with perioperative change in lordosis. SUMMARY OF BACKGROUND DATA: Improvements in sagittal alignment are believed to correlate with improvements in clinical outcomes. Thus, it is important to establish whether intraoperative radiographs predict postoperative improvements in LL or SL. MATERIALS AND METHODS: Electronic medical records were reviewed for patients ≥18 years old who underwent single-level and two-level anterior lumbar interbody fusion with posterior instrumentation between 2016 and 2020. LL, SL, and the lordosis distribution index were compared between preoperative, intraoperative, and postoperative radiographs using paired t tests. A linear regression determined the effect of subsidence on SL and LL. RESULTS: A total of 118 patients met inclusion criteria. Of those, 75 patients had one-level fusions and 43 had a two-level fusion. LL significantly increased following on-table positioning [delta (Δ): 5.7°, P <0.001]. However, LL significantly decreased between the intraoperative to postoperative radiographs at two to six weeks (Δ: -3.4°, P =0.001), while no change was identified between the intraoperative and more than three-month postoperative radiographs (Δ: -1.6°, P =0.143). SL was found to significantly increase from the preoperative to intraoperative radiographs (Δ: 10.9°, P <0.001), but it subsequently decreased at the two to six weeks follow up (Δ: -2.7, P <0.001) and at the final follow up (Δ: -4.1, P <0.001). On linear regression, cage subsidence/allograft resorption was predictive of the Δ SL (ß=0.55; 95% confidence interval: 0.16-0.94; P =0.006), but not LL (ß=0.10; 95% confidence interval: -0.44 to 0.65; P =0.708). CONCLUSION: Early postoperative radiographs may not accurately reflect the improvement in LL seen on intraoperative radiographic imaging, but they are predictive of long-term lumbar sagittal alignment. Each millimeter of cage subsidence or allograft resorption reduces SL by 0.55°, but subsidence does not significantly affect LL. LEVELS OF EVIDENCE: 4.

STRADA-mutant human cortical organoids model megalencephaly and exhibit delayed neuronal differentiation.

Genetic diseases involving overactivation of the mechanistic target of rapamycin (mTOR) pathway, so-called "mTORopathies," often manifest with malformations of cortical development (MCDs), epilepsy, and cognitive impairment. How mTOR pathway hyperactivation results in abnormal human cortical development is poorly understood. To study the effect of mTOR hyperactivity on early stages of cortical development, we focused on Pretzel Syndrome (polyhydramnios, megalencephaly, symptomatic epilepsy; PMSE syndrome), a rare mTORopathy caused by homozygous germline mutations in the STRADA gene. We developed a human cortical organoid (hCO) model of PMSE and examined morphology and size for the first 2 weeks of organoid growth, and cell type composition at weeks 2, 8, and 12 of differentiation. In the second week, PMSE hCOs enlarged more rapidly than controls and displayed an abnormal Wnt pathway-dependent increase in neural rosette structures. PMSE hCOs also exhibited delayed neurogenesis, decreased subventricular zone progenitors, increased proliferation and cell death, and an abnormal architecture of primary cilia. At week 8, PMSE hCOs had fewer deep layer neurons. By week 12, neurogenesis recovered in PMSE organoids, but they displayed increased outer radial glia, a cell type thought to contribute to the expansion of the human cerebral cortex. Together, these findings suggest that megalencephaly in PMSE arises from the expansion of neural stem cells in early corticogenesis and potentially also from increased outer radial glial at later gestational stages. The delayed neuronal differentiation in PMSE organoids demonstrates the important role the mTOR pathway plays in the maintenance and expansion of the stem cell pool.