The efficacy and safety of decompression with interspinous fixation for lumbar spondylolisthesis when compared with posterior lumbar interbody fusion: A pilot study.

Posterior lumbar interbody fusion (PLIF) is widely used to treat degenerative spondylolisthesis because it provides definitive decompression and fixation. Although it has several advantages, it has some disadvantages and risks, such as paraspinal muscle injury, potential intraoperative bleeding, postoperative pain, hardware failure, subsidence, and medical comorbidity. Lumbar decompressive bilateral laminectomy with interspinous fixation (DLISF) is less invasive and can be used on some patients with PLIF, but this has not been reported. To compare the efficacy and safety of DLISF in the treatment of low-grade lumbar spondylolisthesis with that of PLIF. We retrospectively analyzed the medical records of 81 patients with grade I spondylolisthesis, who had undergone PLIF or DLISF and were followed up for more than 1 year. Surgical outcomes, visual analog scale, radiologic outcomes, including Cobb angle and difference in body translation, and postoperative complications were assessed. Forty-one patients underwent PLIF, whereas 40 underwent DLISF. The operative times were 271.0 ±â€…57.2 and 150.6 ±â€…29.3 minutes for the PLIF and DLISF groups, respectively. The estimated blood loss was significantly higher in the PLIF group versus the DLISF group (290.7 ±â€…232.6 vs 122.2 ±â€…82.7 mL, P < .001). Body translation did not differ significantly between the 2 groups. Overall pain improved during the 1-year follow-up when compared with baseline data. Medical complications were significantly lower in the DLISF group, whereas perioperative complications and hardware issues were higher in the PLIF group. The outcomes of DLISF, which is less invasive, were comparable to PLIF outcomes in patients with low-grade spondylolisthesis. As a salvage technique, DLISF may be a good option when compared with PLIF.

Normal Functional Local Alignment and Segmental Motion at the Thoracolumbar Junction: A Cross-Sectional Study of Healthy Subjects.

OBJECTIVE: Several studies have investigated the mechanical behavior of the thoracolumbar spine. However, finding an accurate reference for the normal functional local alignment and segmental motion (SM) at the thoracolumbar junction (TLJ) is challenging. Therefore, this study aimed to assess age- and sex-related changes and differences in local alignment and SM at the TLJ. METHODS: The study recruited healthy subjects aged 20 to 79 without complaints of back pain. Healthy subjects (60 males and 60 females) with appropriate imaging results were enrolled in the study. The subjects were divided into age groups (20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years); each group included 10 subjects of each sex. RESULTS: The SM at the TLJ was small but noticeable, and the motion gradually increased toward the lower level of the TLJ, closer to the lumbar region. No significant differences were observed between male and female subjects in any SM measurements at the TLJ. The SM at the TLJ gradually decreased with age, while local kyphosis of TLJ progressed. The results also showed that the thoracolumbar slope value did not change with age and remained at a mean of -12.8 ± 7.2° (P = 0.893). CONCLUSIONS: This study's results provide valuable guidance for appropriate surgical planning and rehabilitation of patients with spinal diseases or trauma. Furthermore, the results can be the basis for categorizing accurate criteria to evaluate the degree of disability after treatment.

A Capacitive DC-DC Boost Converter with Gate Bias Boosting and Dynamic Body Biasing for an RF Energy Harvesting System.

In this paper, a fully integrated capacitive DC-DC boost converter for ultra-low-power internet of things (IoT) applications operating with RF energy harvesting is proposed. A DC-DC boost converter is needed to boost the low output voltage of the RF energy harvester to provide a high voltage to the load. However, a boost converter operating at a low voltage supplied by ambient RF energy harvesting has a problem in that power conversion efficiency is significantly lowered. The proposed on-chip capacitive DC-DC boost converter simultaneously applies gate bias boosting and dynamic body biasing techniques using only the internal boosted voltage without an additional circuit that increases power loss to boost the voltage, achieving high efficiency at an input voltage as low as 0.1 V. The designed capacitive boost converter achieves a peak power conversion efficiency (PCE) of 33.8% at a very low input voltage of 0.1 V, a 14% improvement over the peak PCE of the conventional cross-coupled charge pump. A maximum peak PCE of 80.1% is achieved at an input voltage of 200 mV and a load current of 3 µA. The proposed capacitive boost converter is implemented with a total flying capacitance of 60 pF, suitable for on-chip integration.

Safety of Gastrostomy Tube Placement in Patients with Advanced Amyotrophic Lateral Sclerosis With Noninvasive Ventilation.

BACKGROUND: In patients with amyotrophic lateral sclerosis (ALS), bulbar muscle dysfunction can occur, which eventually requires the initiation of enteral tube feeding. However, there is no consensus on the optimal timing for the gastrostomy or the proper ventilator support method during the procedure. We aimed to investigate the safe range of gastrostomy according to respiratory support status and forced vital capacity (FVC) % of predicted values classification and to compare the safety of noninvasive and invasive mechanical ventilation during the procedure in ALS patients with FVC < 30% of predicted. METHODS: A total of 477 patients diagnosed with ALS at our institution from January 1, 2009, to December 31, 2018, were evaluated, and 105 patients were enrolled in this study. All medical records covering ventilation status and complications within 6 months to 1 year after the initial gastrostomy were gathered and reviewed. RESULTS: The gastrostomy procedure was considered safe regardless of FVC status or modality of respiratory support. There were complications related to the gastrostomy procedure in 6 of 105 patients and all were managed through conservative care. The incidence of complications, including respiratory ones, for noninvasive and invasive positive pressure ventilation was 5.5% and 9.6%, respectively, which were not statistically significantly different (P = .294). CONCLUSION: The procedure and tube placement of a gastrostomy can be safely performed in ALS patients with minimal FVC regardless of ventilation invasiveness. We suggest that there should be a new standard for FVC % of predicted to facilitate performing gastrostomy in ALS patients.

Clinical warning signs of life-threatening hematochezia in neurosurgical patients with long-term bed rest: Three cases report.

RATIONALE: Patients with long term bed rest in intensive care unit after neurosurgery could experience splanchnic hypoperfusion. These patients have several other medical conditions that exacerbate splanchnic hypoperfusion during treatment and the splanchnic hypoperfusion could result in "stress-induced intestinal necrosis", which could cause massive hematochezia. We report here the experience of life-threatening hematochezia in 3 patients who underwent brain surgery in our institution. PATIENTS CONCERNS: One female patient (72-year-old) and 2 male patients (58- and 35-year-old) were admitted to our institution because of traumatic intracerebral hemorrhage, subarachnoid hemorrhage due to a ruptured anterior communicating artery, and subarachnoid hemorrhage with unknown cause respectively. All patients underwent emergency brain surgery for diagnosis and treatment. After surgery, they all experienced long-term bed rest in intensive care unit. Hematochezia occurred on postoperative day 15, 17, and 49, respectively. DIAGNOSES: All of the patients were assessed by abdomen/pelvis computed tomography and underwent a colonoscopy. INTERVENTIONS: The female patient underwent embolization through pelvic arteriography and epinephrine injection through colonoscopy, but a total colectomy and ileostomy was performed due to refractory hematochezia. 58-year-old male patient had a laparoscopic ileostomy for the bowel rest. The other patient underwent nil per os and conservative treatment for 2 weeks. OUTCOMES: The female patient was discharged without further treatment plan, 58-year-old male patient survived after laparoscopic ileostomy, while the other patient survived after 2 weeks of nil per os. LESSON: Abdominal symptoms, such as hematochezia, should be actively managed in neurosurgical patients who are undergoing long-term bed rest in an intensive care unit under physiologically stressful medical conditions.

Thoracolumbar burst fractures in patients with neurological deficit: Anterior approach versus posterior percutaneous fixation with laminotomy.

BACKGROUND: Thoracolumbar burst fractures (TLBFs) are the most common spinal trauma; however, their appropriate management has not yet been determined. In this study, we aimed to compare the clinical and radiological results of percutaneous pedicle screw fixation (PPSF) following posterior decompression technique versus anterior corpectomy and fusion technique for the treatment of TLBFs. METHODS: A total of 46 patients (2002-2015) with TLBFs were included in this study. The inclusion criteria were a single-level Magerl type A3 burst fracture of the thoracolumbar junctional spine (T12-L2). The patients were divided into two groups; Group A (22 patients) underwent anterior corpectomy and fusion, and Group B (24 patients) underwent PPSF after posterior decompression. Anterior corpectomy and fusion surgery were performed in 22 cases before April 2009, and PPSF following posterior decompression technique was used in 24 cases since then. For radiological assessment, the kyphosis angle was measured preoperatively, early postoperatively, and at the last follow-up using the Cobb angle. Mean correction of the Cobb angle after surgery, and loss of correction between the immediate postoperative and final Cobb angle were calculated accordingly. All neurological deficits were identified in the initial evaluation and graded using the American Spinal Injury Association(ASIA) grading system. Perioperative parameters including operation time, amount of blood loss, and mean hospital stay were also evaluated. RESULTS: The patients comprised 17 males and 5 females in Group A and 13 males and 11 females in Group B. In terms of the involved levels, there were three cases of T12, twelve L1, and seven L2 in Group A and one case of T12, thirteen L1, and ten L2 in Group B. The mean follow-up duration was 44.9 months in Group A and 14.7 months in Group B. The kyphotic angle was significantly corrected after surgery by 6.4° in Group A (p = 0.001) and 9.2° in Group B (p < 0.001). Among patients with neurological deficit, 11 of 15 in Group A and 20 of 23 in Group B demonstrated improvement by at least one ASIA grade at the final observation. However, there was no significant difference in neurological improvement between the two groups (p = 0.13). Mean operation time was significantly shorter (p < 0.001) and mean blood loss was significantly less (p < 0.001) in Group B than in Group A. Mean hospital stay was also significantly shorter in Group B (p < 0.001). CONCLUSIONS: Spinal canal decompression through small laminectomy followed by PPSF in the treatment of TLBFs with neurological deficits offers excellent clinical and radiological improvement as well as biomechanical stability. Furthermore, this can be a safe and effective surgical option with the advantage of less invasiveness in the treatment of TLBFs.

Clinical implication of maximal voluntary ventilation in myotonic muscular dystrophy.

Patients with myotonic muscular dystrophy type 1 (DM1) tend to exhibit earlier respiratory insufficiency than patients with other neuromuscular diseases at similar or higher forced vital capacity (FVC). This study aimed to analyze several pulmonary function parameters to determine which factor contributes the most to early hypercapnia in patients with DM1.We analyzed ventilation status monitoring, pulmonary function tests (including FVC, maximal voluntary ventilation [MVV], and maximal inspiratory and expiratory pressure), and polysomnography in subjects with DM1 who were admitted to a single university hospital. The correlation of each parameter with hypercapnia was determined. Subgroup analysis was also performed by dividing the subjects into 2 subgroups according to usage of mechanical ventilation.Final analysis included 50 patients with a mean age of 42.9 years (standard deviation = 11.1), 46.0% of whom were male. The hypercapnia was negatively correlated with MVV, FVC, forced expiratory volume in 1 second (FEV1), and their ratios to predicted values in subjects with myotonic muscular dystrophy type 1. At the same partial pressure of carbon dioxide, the ratio to the predicted value was lowest for MVV, then FEV1, followed by FVC. Moreover, the P values for differences in MVV and its ratio to the predicted value between ventilator users and nonusers were the lowest.When screening ventilation failure in patients with DM1, MVV should be considered alongside other routinely measured parameters.

Importance of collateral venous circulation on indocyanine green videoangiography in intracranial meningioma resection: direct evidence for venous compression theory in peritumoral edema formation.

OBJECTIVE: Indocyanine green videoangiography (ICGVA) has been used in many neurosurgical operations, including vascular and brain tumor fields. In this study, the authors applied ICGVA to intracranial meningioma surgery and evaluated it usefulness with attention to collateral venous flow. METHODS: Forty-two patients with intracranial meningioma who underwent ICGVA during microsurgical resection were retrospectively analyzed. For ICGVA, the ICG was injected intravenously at the standard dose of 12.5 mg before and/or after tumor resection. Intravascular fluorescence from blood vessels was imaged through a microscope with a special filter and infrared excitation light to illuminate the operating field. The authors assessed the benefits of ICGVA and analyzed its findings with preoperative radiological findings on MRI. RESULTS: ICGVA allowed real-time assessment of the patency and flow direction in very small peritumoral vessels in all cases. A safe dural incision could also be done based on information from ICGVA. The collateral venous channel due to venous obstruction of tumoral compression was found in 10 cases, and venous flow restoration after tumor resection was observed promptly after tumor resection in 4 cases. Peritumoral brain edema (PTBE) was observed on preoperative T2-weighted MRI in 19 patients. The presence of collateral venous circulation or flow restoration was significantly related to PTBE formation in multivariate analysis (p = 0.001; HR 0.027, 95% CI 0.003-0.242). CONCLUSIONS: ICGVA, an excellent method for monitoring blood flow during meningioma resection, provides valuable information as to the presence of venous collaterals and flow restoration. Furthermore, the fact that the presence of venous collaterals was found to be associated with PTBE may directly support the venous theory as the pathogenesis of PTBE formation.

Visual outcome after endoscopic third ventriculostomy for hydrocephalus.

PURPOSE: Hydrocephalus-related symptoms are mostly improved after successful endoscopic third ventriculostomy (ETV). However, visual symptoms can be different. This study was focused on visual symptoms. We analyzed the magnetic resonance images (MRI) of the orbit and visual outcomes. METHODS: From August 2006 to November 2016, 50 patients with hydrocephalus underwent ETV. The male-to-female ratio was 33:17, and the median age was 61 years (range, 5-74 years). There were 18 pediatric and 32 adult patients. Abnormal orbital MRI findings included prominent subarachnoid space around the optic nerves and vertical tortuosity of the optic nerves. We retrospectively analyzed clinical symptoms, causes of hydrocephalus, ETV success score (ETVSS), ETV success rate, ETV complications, orbital MRI findings, and visual impairment score (VIS). RESULTS: The median duration of follow-up was 59 months (range, 3-113 months). The most common symptoms were headache, vomiting, and gait disturbance. Visual symptoms were found in 6 patients (12%). The most common causes of hydrocephalus were posterior fossa tumor in 13 patients, pineal tumor in 12, aqueductal stenosis in 8, thalamic malignant glioma in 7, and tectal glioma in 4. ETVSS was 70 in 3 patients, 80 in 34 patients, and 90 in 13 patients. ETV success rate was 80%. ETVSS 70 showed the trend in short-term survival compared to ETVSS 90 and 80. ETV complications included epidural hematoma requiring operation in one patient, transient hemiparesis in two patients, and infection in two patients. Preoperative abnormal orbital MRI findings were found in 18 patients and postoperative findings in 7 patients. Four of six patients with visual symptoms had abnormal MR findings. Three patients did not show VIS improvement, including two with severe visual symptoms. CONCLUSIONS: Patients with severe visual impairment were found to have bad outcomes. The visual symptoms related with increased intracranial pressure should be carefully monitored and controlled to improve outcomes.

Multiplex Ligation-Dependent Probe Amplification in X-linked Recessive Muscular Dystrophy in Korean Subjects.

PURPOSE: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are similar genetic disorders whose patterns of mutation and disease phenotypes might be expected to show differences among different countries. We analyzed multiplex ligation-dependent probe amplification (MLPA) data in a large number of Korean patients with DMD/BMD. MATERIALS AND METHODS: We obtained 130 positive MLPA results (86 DMD, 27 BMD, and 17 female carriers) from 272 candidates (237 clinically suspected patients and 35 possible female carriers) who took part in this study. We analyzed the mutation patterns among 113 patients diagnosed by MLPA and calculated deletion/duplication percentages from a total of 128 patients, including 15 patients who were diagnosed using methods other than MLPA. We also analyzed hot spot locations among the 130 MLPA-positive results. RESULTS: Most mutations were detected in a central hot spot region between exons 44 and 55 (80 samples, 60.6%). Unlike previous reports, a second frequently observed hot spot near the 5'-end was not distinctive. MLPA detected deletions in specific exons in 92 patients with DMD/BMD (71.8%) and duplications in 21 patients (16.4%). CONCLUSION: Our MLPA study of a large number of Korean patients with DMD/BMD identified the most frequent mutation hot spot, as well as a unique hot spot pattern. DMD gene mutation patterns do not appear to show significant ethnic differences.