Usefulness and Safety of Gelatin-Thrombin Matrix Sealants in Minimally Invasive Microscopic Discectomy.

Objective This study aimed to evaluate the usefulness and safety of gelatin-thrombin matrix sealants (GTMSs) in minimally invasive microscopic discectomy, a surgical procedure commonly used to treat lumbar disc herniation. Materials and Methods Out of 484 patients who underwent minimally invasive microscopic discectomy between April 2018 and December 2022, 35 patients with a history of surgery at the same level were excluded, resulting in a total of 449 patients included in the study. Among them, 316 patients were treated using GTMS, whereas 133 were treated using collagen-based absorbable local hemostatic agents. Patient characteristics, surgical duration, intraoperative blood loss, postoperative drainage volume, intraoperative dural injury, and incidence of postoperative epidural hematoma were analyzed and compared between the two groups. Results No significant differences in patient demographics were observed between the two groups, except for activated partial thromboplastin time and prothrombin time. Although there were no significant differences in the mean surgical time and intraoperative blood loss between the two groups, they tended to be shorter and less in the GTMS group (56.3 ± 20.2 vs. 58.2 ± 20.4 minutes [ p = 0.36] and 10.0 ± 15.4 vs. 11.8 ± 8.3 g [ p = 0.20]). The volume of postoperative drainage was significantly lower in the GTMS group than that in the comparison group (35.3 ± 21.8 vs. 49.5 ± 34.1 g [ p < 0.01]). There was a trend indicating a difference in the number of intraoperative dural injuries and the need for reoperation due to postoperative epidural hematoma (2 vs. 3 ± 20.4 minutes [ p = 0.21] and 1 vs. 2 [ p = 0.16]). Conclusion The use of a GTMS in minimally invasive microscopic discectomy appears to be beneficial in reducing postoperative drainage volume. It has also been shown that it may improve clinical outcomes such as intraoperative dural injury and postoperative epidural hematoma. Furthermore, further consideration of the medical economic impact is required.

Surgical treatment for recurrent thoracic ventral intradural arachnoid cyst secondary to tuberculous meningitis: a case report.

INTRODUCTION: Spinal intradural arachnoid cysts (SIACs) are rare spinal entities that are categorized as primary or secondary pathologies. Secondary cysts can arise from various traumatic or inflammatory causes including subarachnoid hemorrhage, intrathecal injection or surgery, and infectious meningitis/arachnoiditis. Only a few cases of SIAC secondary to tuberculous meningitis have been previously reported, without details of the surgical treatment. CASE PRESENTATION: A 27-year-old woman diagnosed with tuberculous meningitis developed myelopathy caused by thoracic ventral SIAC and intradural abscess. The patient underwent abscess evacuation and cyst fenestration; however, cyst recurrence occurred. The 2nd surgery consisted of cyst resection via a posterolateral approach with expansive duraplasty and spinal arthrodesis. Re-recurrence occurred, and at the 3rd surgery, cyst-subarachnoid bypass was performed. One year after the 3rd surgery, the myelopathic symptoms recovered, and MR images demonstrated a decreased cyst size. DISCUSSION: Here, we report a rare case of recurrent thoracic SIAC secondary to tuberculous meningitis and arachnoiditis. Simple fenestration is associated with a high risk of recurrence in this pathology. Ventrally located thoracic cysts can be approached with posterolateral approach with pedicles resected followed by instrumented arthrodesis. Even in cases involving gross total resection of the cyst wall, there is a risk of recurrence. In such cases, cyst-subarachnoid bypass with a large-diameter tube can be effective.

Immediate Effects, Detailed Clinical Outcomes, and Prognostic Factors of Chemonucleolysis Using Condoliase for Lumbar Disc Herniation.

Chemonucleolysis utilizing condoliase is a minimally invasive treatment for lumbar disc herniation (LDH) aimed at reducing intervertebral disc pressure and enhancing symptoms. In this study, lower limb pain was measured using the numeric rating scale (NRS) the day after treatment and 1 and 3 months after treatment. Prognostic factors were assessed, categorizing participants into an improvement group (I-group) for NRS lower limb pain scores of ≥3.5 and a non-improvement group (N-group) for scores of <3.5. This study included a total of 225 patients treated between April 2020 and March 2023. The mean age was 46.5 ± 16.5 years, with 151 males. The mean duration of illness was 6.2 ± 8.52 months. As of the day after treatment, 60 cases were classified into the I-group, 118 cases at 1 month after surgery, and 152 cases at 3 months after surgery. The disease duration before treatment was significantly shorter in the I-group at 1 (8.19 ± 8.74 [I-group] vs. 5.17 ± 8.04 [N-group] months) and 3 months (8.51 [I-group] ± 7.35 vs. 5.69 ± 8.87[N-group] months) after treatment. The comparison of baseline leg pain NRS shows a difference in leg pain NRS in the I-group when compared on the day after treatment (6.02 ± 2.64 [I-group] vs. 7.50 ± 1.79 [N-group]), 1 (5.13 ± 2.69 [I-group] vs. 7.58 ± 1.66 [N-group]), and 3 months (4.42 ± 2.70 [I-group] vs. 7.34 ± 1.77 [N-group]). Chemonucleolysis using condoliase for LDH can improve symptoms the day after treatment and can be a minimally invasive treatment to avoid surgery.

Accuracy of Percutaneous Pedicle Screw Insertion Technique with Conventional Dual Fluoroscopy Units and a Retrospective Comparative Study Based on Surgeon Experience.

Study Design Retrospective comparative study. Objective To evaluate the accuracy of percutaneous pedicle screw (PPS) placement and intraoperative imaging time using dual fluoroscopy units and their differences between surgeons with more versus less experience. Methods One hundred sixty-one patients who underwent lumbar fusion surgery were divided into two groups, A (n = 74) and B (n = 87), based on the performing surgeon's experience. The accuracy of PPS placement and radiation time for PPS insertion were compared. PPSs were inserted with classic technique under the assistance of dual fluoroscopy units placed in two planes. The breach definition of PPS misplacement was based on postoperative computed tomography (grade I: no breach; grade II: <2 mm; grade III: ≤2 to <4 mm). Results Of 658 PPSs, only 21 screws were misplaced. The breach rates of groups A and B were 3.3% (grade II: 3.4%, grade III: 0%) and 3.1% (grade II: 2.6%, grade III: 0.6%; p = 0.91). One patient in grade III misplacement had a transient symptom of leg numbness. Median radiation exposure time during PPS insertion was 25 seconds and 51 seconds, respectively (p < 0.01). Conclusions Without using an expensive imaging support system, the classic technique of PPS insertion using dual fluoroscopy units in the lumbar and sacral spine is fairly accurate and provides good clinical outcomes, even among surgeons lacking experience.

Effects of handling parameters on hydrogen sulfide emission from stored dairy manure.

Hydrogen sulfide (H2S) emission from liquid manure in the process preceding field application is an important issue in fertigation systems. Given that H2S poses a significant health risk, it is important to determine the effects of different handling parameters on H2S emissions to prevent health risks to farmers. In this study, the effects of total solids (TS; 3, 5, 7, 9, and 11%) and mixing speed (100, 200, 300, and 400 rpm), duration (5, 15, 30, and 60 min), and frequency (one, two, three, and four times a day) on H2S emissions from two different dairy manures were investigated. The results indicate that the quantity of sulfur-containing substrate intake determines the potential of dairy manure to emit H2S because manure from cows fed with concentrate-based feed generates higher amounts of H2S than manure from cows fed with forage-based feed. The H2S concentration increased with TS concentration and reached a maximum of 1133 ppm at a TS of 9%; thereafter, it decreased with further increases in TS concentration. H2S emission increased with mixing speed with a peak concentration of 3996 ppm at 400 rpm. A similar trend was observed for mixing duration. However, there were no significant differences between the amounts H2S emitted at different frequencies of mixing (P > 0.05). The results indicate that mixing speed, duration, and TS are the major determinants of the quantity of H2S emitted from dairy manure. Therefore, to prevent health risks associated with H2S emission from dairy manure, it is recommended that the mixing speed and duration should be kept as low as possible, while a TS concentration of above 9% should be applied during the fertigation of dairy manure.

Effects of inspiratory rise time on triggering work load during pressure-support ventilation: a lung model study.

BACKGROUND: The rise in inspiratory flow is important during patient-triggered ventilation. Many ventilators incorporate a function to control the time to reach the targeted airway pressure (inspiratory rise time). However, it has not been clarified how inspiratory rise time affects inspiratory work load under various ventilator settings. In a bench study we investigated the effect of inspiratory rise time on inspiratory work load during pressure-support ventilation (PSV). METHODS: We studied 6 ICU ventilators. We measured flow and pressure at the airway opening (P(ao)) at PEEP of 5 cm H(2)O, pressure-support of 5 cm H(2)O and 10 cm H(2)O, 4 triggering sensitivities, and inspiratory drives 300 mL, 500 mL, and 700 mL. The inspiratory-rise-time setting was not consistent between the ventilators, and we chose 3 inspiratory-rise-time levels with each ventilator. The inspiratory delay time (DT) was defined as the time between the onset of inspiration and the return of P(ao) to baseline, and was divided into 2 parts at the point of the lowest P(ao): before the lowest P(ao) (DT(1)), and after the lowest P(ao) (DT(2)). As an indicator of inspiratory work load we calculated the pressure-time-product (PTP) of the P(ao) over the DT. PTP was also divided into PTP(1) and PTP(2), at the point of the lowest P(ao). RESULTS: Short inspiratory rise time reduced DT(2), PTP(1), and PTP(2), regardless of the pressure-support level, triggering sensitivity, or inspiratory drive. However, the inspiratory-rise-time setting did not affect DT(1). The PTP(1), PTP(2), and DT(2) values differed significantly among the ventilators. A combination of short inspiratory rise time, high PSV, and sharp triggering sensitivity resulted in the smallest PTP and DT values. CONCLUSIONS: Short inspiratory rise time decreased inspiratory work load, regardless of the pressure-support level, triggering sensitivity, or inspiratory drive. Inspiratory work load can be maximally lowered by a combination of a short inspiratory rise time, a sharp triggering sensitivity, and a high inspiratory pressure-support level for a given patient's inspiratory effort.

Vitrectomy with internal limiting membrane peeling for macular retinoschisis and retinal detachment without macular hole in highly myopic eyes.

PURPOSE: To report anatomic and visual improvement following vitrectomy with internal limiting membrane (ILM) peeling for two highly myopic patients with retinoschisis and/or retinal detachment without a macular hole. DESIGN: Two interventional case reports. METHODS: Two highly myopic patients who had retinoschisis and/or retinal detachment without a full-thickness macular hole underwent vitrectomy, internal limiting membrane peeling, and long-acting gas injection. Main outcome measures included best-corrected visual acuity, biomicroscopic appearance, and optical coherent tomography finding. RESULTS: Vitrectomy with ILM peeling results in biomicroscopic, functional, and tomographic improvement in both patients, for follow-up periods of 12 months and 8 months, respectively. CONCLUSIONS: Vitrectomy with ILM peeling and gas tamponade is an effective method for retinoschisis and/or retinal detachment without a macular hole in highly myopic patients.

Visual field defects after uneventful vitrectomy for epiretinal membrane with indocyanine green-assisted internal limiting membrane peeling.

PURPOSE: To report visual field defects after vitrectomy for epiretinal membrane with indocyanine green (ICG)-assisted internal limiting membrane (ILM) peeling. DESIGN: Interventional consecutive case series. METHODS: A retrospective review of 16 eyes of 16 patients who underwent vitrectomy for idiopathic epiretinal membrane. Indocyanine green-assisted ILM peeling was performed in 7 of 16 eyes. The main outcome measure was postoperative visual field. RESULTS: Four of seven eyes (57%) with ICG-assisted ILM peeling had visual field defects postoperatively. The field defects identified were nasal in three eyes; in the fourth eye, the visual field was constricted to approximately 30 degrees. None of the nine eyes without ICG-assisted ILM peeling had a visual field defect. CONCLUSIONS: Peripheral visual field defects may occur after vitrectomy with ICG-assisted ILM peeling. Although the cause of the defects is unclear, the potential role of ICG toxicity requires further investigation.