Surgical Outcome of Percutaneous Endoscopic Interlaminar Lumbar Discectomy for Highly Migrated Disk Herniation.

STUDY DESIGN: Technical report. OBJECTIVE: To present a detailed surgical technique for percutaneous endoscopic interlaminar discectomy (PEID) for highly migrated disk herniation. SUMMARY OF BACKGROUND DATA: Percutaneous lumbar endoscopic discectomy for highly migrated disk herniation is still challenging even for an experienced surgeon. Because of the risk of failure and technical difficulty, open discectomy is recommended for a high-grade migration. However, past reports focused on the transforaminal approach (percutaneous endoscopic transforaminal discectomy) and may give a biased impression. We may overlook the merit of PEID. The surgical procedure for PEID is similar to a traditional open discectomy and the range of approach could be widened by the inclined introduction and pivoting motion of an endoscope. METHODS: Eighteen consecutive patients (M:F=12:6; age, 56±15 y) with highly migrated disk herniation were enrolled for the present study. The disk material was migrated superiorly in 7 patients (L4-5, 4; L5-S1, 2; L2-3, 1) and inferiorly in 11 patients (L4-5, 6; L3-4, 4; L5-S1, 1). PEID was applied in 17 patients and PETD was performed for L2-3 disk herniation. The follow-up period was 16±12 months. The outcome was graded using the MacNab criteria. RESULTS: Complete removal of the disk material was confirmed with magnetic resonance imaging in 16 patients (success rate 89%). Revision operation was necessary in 2 patients with inferior migration from L4-5. The residual disk was removed through the L5-S1 laminar window 2 days after surgery with excellent outcome at the last follow-up. The outcome at the last follow-up was excellent in 12 patients, good in 3, fair in 2, and poor in 1. Dural tear was suspected in 1 patient without any further problems and there was no recurrence during follow-up. CONCLUSIONS: PEID may be applied comfortably even for less-experienced surgeons because of the familiar anatomy with open surgery.

Symmetrically medial bony gutters for open-door laminoplasty.

STUDY DESIGN: Observational cohort study. OBJECTIVE: The authors modified open-door laminoplasty in a manner that creates a bony gutter symmetrically and more medially away from the medial border of the lateral mass. SUMMARY OF BACKGROUND DATA: Cervical laminoplasty is becoming popular, but there was no definite position of bony gutter in performing open-door laminoplasty. METHODS: All of the patients underwent our modified open-door laminoplasty with medial bony gutters. The bony gutter on the open side was made 3 mm medially apart from the medial border of the lateral mass, and an opposite gutter on the hinge side was drilled symmetrically to that on the open side while preserving the ventral cortex. The lamina was kept elevated using titanium miniplates bridging the lamina and facet joint on the open side. On the computed tomography, distance of the bony gutters and the cross-sectional area were measured from C4 to C6. RESULTS: This study included consecutive 61 patients (46 men and 15 women; mean age, 61.6 y old). The average distance of the right bony gutter was 3.43 mm and that of left bony gutter was 3.35 mm. The average cross-sectional area of preoperative and postoperative computed tomography was 189.9 and 281.8 mm in all patients, respectively. In all patients, although bony gutter was placed medially, the spinal canal area was expanded significantly (P < 0.0001). Postoperative C5 palsy developed in one of the 61 patients (1.6%). Compared with patients without C5 palsy, the right bony gutter was placed much closer to the medial border of the lateral mass in a patient with C5 palsy in whom we opened the lamina on the right side. CONCLUSIONS: Our modified open-door laminoplasty with symmetrically and medially placed bony gutters produced low incidence of postoperative C5 palsy with effective expansion of the spinal canal area.

Spread of subarachnoid sensory block with hyperbaric bupivacaine in second trimester of pregnancy.

STUDY OBJECTIVE: To compare the spread of subarachnoid sensory block with hyperbaric bupivacaine in second trimester pregnant and non-pregnant women. DESIGN: Prospective study. SETTING: University teaching hospital. PATIENTS: 44 ASA physical status I and II women patients, 22 of whom were in their second trimester of pregnancy undergoing cervical cerclage, and 22 non-pregnant women scheduled for perianal surgery. INTERVENTIONS: The extent of sensory block and hemodynamic changes were assessed. MEASUREMENTS: Number of dermatomes blocked was determined by testing for pinprick; systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured at 3, 5, 10, 15, 30 and 60 minutes. MAIN RESULTS: Maximal sensory block was higher in the second trimester of the pregnant group by three dermatomes than the non-pregnant group. There were no statistically significant differences in SBP, DBP, or HR changes between the groups. CONCLUSION: Pregnant women in the second trimester exhibit enhanced spread of spinal analgesia with hyperbaric bupivacaine more so than non-pregnant women.

Porcine PD-L1: cloning, characterization, and implications during xenotransplantation.

BACKGROUND: Effective intervention achieved by manipulating cell-mediated xenogeneic immune responses would critically increase the clinical feasibility of xenotransplantation as immediate hyperacute rejections become controllable through genetic modulations of donor organs. Endogenous negative regulatory signals like the programmed death 1 (PD-1)-programmed death ligand 1 (PD-L1) system are candidate targets for the control of cell-mediated xenogeneic immune response. METHODS: A porcine PD-L1 molecule was cloned using RACE (rapid amplification of cDNA ends) technology based on the human PD-L1 sequence. The functional effects of cloned porcine PD-L1 were tested on human CD4(+) T cell activation using porcine PD-L1-transfected bystander cells. Cellular proliferation was monitored by [3H] thymidine incorporation, and human T cell apoptosis was measured by flow cytometry. RESULTS: Porcine PD-L1 (GenBank accession number AY837780) was found to have 73.8% sequence homology with human PD-L1 and to contain two immunoglobulin domains in its extracellular region. Moreover, porcine PD-L1 expressed on Chinese hamster ovary (CHO) cells inhibited human CD4(+) T cell proliferation stimulated with anti-CD3 only or anti-CD3 plus anti-CD28. Percentages of apoptotic activated human T cells increased by over 30% in the presence of porcine PD-L1/CHO cells, and the addition of recombinant human PD-1-Fc fusion proteins during human T cell activation reversed the inhibitory effects of porcine PD-L1. CONCLUSIONS: Cloned porcine PD-L1 showed high sequence homology with human PD-L1 and a similar molecular structure. Moreover, porcine PD-L1 inhibited human CD4(+) T cell activation in human PD-1-dependent manner, and this involved activated T cell apoptosis. The authors suggest that PD-1-PD-L1 might play an important endogenous immune regulatory role during xenogeneic transplantation, and that the effective application of this system would improve transplanted xenogeneic organ survival.