A Novel LIBS Sensor for Sample Examinations on a Crime Scene.

In this work, we present a compact LIBS sensor developed for characterization of samples on a crime scene following requirements of law enforcement agencies involved in the project. The sensor operates both in a tabletop mode, for aside measurements of swabbed materials or taken fragments, and in handheld mode where the sensor head is pointed directly on targets at the scene. The sensor head is connected via an umbilical to an instrument box that could be battery-powered and contains also a color camera for sample visualization, illumination LEDs, and pointing system for placing the target in focus. Here we describe the sensor's architecture and functionalities, the optimization of the acquisition parameters, and the results of some LIBS measurements. On nano-plotted traces at silica wafer and in optimized conditions, for most of the elements the detection limits, in term of the absolute element masses, were found to be below 10 picograms. We also show results obtained on some representative materials, like fingerprints, swabbed soil and gunshot residue, varnishes on metal, and coated plastics. The last, solid samples were used to evaluate the depth profiling capabilities of the instrument, where the recognition of all four car paint layers was achieved.

Turbulence in surgical suction heads as detected by MRI.

BACKGROUND: Blood loss is common during surgical procedures, especially in open cardiac surgery. Allogenic blood transfusion is associated with increased morbidity and mortality. Blood conservation programs in cardiac surgery recommend re-transfusion of shed blood directly or after processing, as this decreases transfusion rates of allogenic blood. But aspiration of blood from the wound area is often associated with increased hemolysis, due to flow induced forces, mainly through development of turbulence. METHODS: We evaluated magnetic resonance imaging (MRI) as a qualitative tool for detection of turbulence. MRI is sensitive to flow; this study uses velocity-compensated T1-weighted 3D MRI for turbulence detection in four geometrically different cardiotomy suction heads under comparable flow conditions (0-1250 mL/min). RESULTS: Our standard control suction head Model A showed pronounced signs of turbulence at all flow rates measured, while turbulence was only detectable in our modified Models 1-3 at higher flow rates (Models 1 and 3) or not at all (Model 2). CONCLUSIONS: The comparison of flow performance of surgical suction heads with different geometries via acceleration-sensitized 3D MRI revealed significant differences in turbulence development between our standard control Model A and the modified alternatives (Models 1-3). As flow conditions during measurement have been comparable, the specific geometry of the respective suction heads must have been the main factor responsible. The underlying mechanisms and causative factors can only be speculated about, but as other investigations have shown, hemolytic activity is positively associated with degree of turbulence. The turbulence data measured in this study correlate with data from other investigations about hemolysis induced by surgical suction heads. The experimental MRI technique used showed added value for further elucidating the underlying physical phenomena causing blood damage due to non-physiological flow.

Spinal epidural hematoma without significant trauma in children: two case reports and review of the literature.

BACKGROUND: Spinal epidural hematoma without significant trauma is a rare condition with potentially severe outcome. This case report and systematic review of the literature illustrates the clinical presentation, risk factors, evaluation, treatment and outcomes of spinal epidural hematoma without significant trauma in children. CASE PRESENTATION: We report one case of a 7-year-old girl who developed a neck pain after minor cervical sprain. MRI showed a right posterior epidural hematoma extending from C2/3 to T1. The hematoma was surgically evacuated, and the histopathology showed an arteriovenous malformation. Postoperative MRI showed complete evacuation of the hematoma and no residual vascular malformation. We report a second ASE with idiopathic spinal epidural hematoma of a 4½-year-old boy presenting with neck pain. MRI showed a right-sided latero-posterior subacute spinal epidural hematoma at C3-C5. Owing to the absence of any neurological deficit, the patient was treated conservatively. MRI at 3 months showed complete resolution of the hematoma. CONCLUSIONS: Spinal epidural hematoma without significant trauma in children is a rare condition. It may present with unspecific symptoms. Screening for bleeding diathesis is warranted and neuroradiologic follow-up is essential to rule out vascular malformation. Whereas most children have a favorable outcome, some do not recover, and neurological follow-up is required.

Sonography of the optic nerve sheath diameter before and after microsurgical closure of a dural CSF fistula in patients with spontaneous intracranial hypotension - a consecutive cohort study.

OBJECTIVE: Spontaneous intracranial hypotension is caused by spinal cerebrospinal fluid leakage. Patients with orthostatic headaches and cerebrospinal fluid leakage show a decrease in optic nerve sheath diameter upon movement from supine to upright position. We hypothesized that the decrease in optic nerve sheath diameter upon gravitational challenge would cease after closure of the leak. METHODS: We included 29 patients with spontaneous intracranial hypotension and refractory symptoms admitted from 2013 to 2016. The systematic workup included: Optic nerve sheath diameter sonography, spinal MRI and dynamic myelography with subsequent CT. Microsurgical sealing of the cerebrospinal fluid leak was the aim in all cases. RESULTS: Of 29 patients with a proven cerebrospinal fluid leak, one declined surgery. A single patient was lost to follow-up. In 27 cases, the cerebrospinal fluid leak was successfully sealed by microsurgery. The width of the optic nerve sheath diameter in supine position increased from 5.08 ± 0.66 mm before to 5.36 ± 0.53 mm after surgery ( p = 0.03). Comparing the response of the optic nerve sheath diameter to gravitational challenge, there was a significant change from before (-0.36 ± 0.32 mm) to after surgery (0.00 ± 0.19 mm, p < 0.01). In parallel, spontaneous intracranial hypotension-related symptoms resolved in 26, decreased in one and persisted in a single patient despite recovery of gait. CONCLUSIONS: The sonographic assessment of the optic nerve sheath diameter with gravitational challenge can distinguish open from closed spinal cerebrospinal fluid fistulas in spontaneous intracranial hypotension patients. A response to the gravitational challenge, that is, no more collapse of the optic nerve sheath while standing up, can be seen after successful treatment and correlates with the resolution of clinical symptoms. Sonography of the optic nerve sheath diameter may be utilized for non-invasive follow-up in spontaneous intracranial hypotension.

Minimally invasive versus conventional extracorporeal circulation circuits in patients undergoing coronary artery bypass surgery: a propensity-matched analysis.

OBJECTIVES: Minimally invasive extracorporeal circulation circuits provide several advantages compared to conventional extracorporeal circulation circuits. We compared the results of a minimally invasive extracorporeal circulation system with those of conventional extracorporeal circulation system, in patients undergoing isolated coronary artery bypass grafting. METHODS: We identified 753 consecutive patients who underwent coronary artery bypass grafting at our centre between October 2014 and September 2016. These patients were divided into two groups: a minimally invasive extracorporeal circulation group (M, n = 229) and a conventional extracorporeal circulation group (C, n = 524). Baseline parameters, details of cardiac surgery as well as postoperative complications and outcomes were compared by means of a propensity-matched analysis of 180 matched pairs. RESULTS: The median EuroSCORE II was 1.3%. Transfusion requirement of packed red blood cells (p = 0.002) was lower in Group M compared to conventional extracorporeal circulation systems. There were no differences in hospital mortality or in rates of adverse events between the matched groups. Total in-hospital mortality of the cohort was 1.7%. CONCLUSION: The use of minimally invasive extracorporeal circulation is associated with a significantly lower use of blood products after isolated coronary revascularisation. There were no differences concerning duration of surgery, complication rates and mortality between the groups. Therefore, the application of minimally invasive extracorporeal circulation systems should be considered as preferred technique in isolated coronary artery bypass grafting procedures.

Cryptogenic Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension: Role of Dynamic CT Myelography.

Purpose To propose a modified dynamic CT myelographic technique to locate cerebrospinal fluid (CSF) leaks, also known as cryptogenic leaks, in patients with spontaneous intracranial hypotension (SIH) in whom previous imaging did not show the dural breach. Materials and Methods This retrospective analysis included 74 consecutive patients with SIH and a myelographically proven CSF leak who were evaluated between February 2013 and October 2017. In 14 patients, dynamic CT myelography in the prone or lateral position showed the exact leakage point after unsuccessful previous imaging. During image analysis, the first time point showing extrathecal contrast material was defined as the site of dural breach point. Results Mean population age was 44 years (range, 25-65 years [nine women; mean age, 44 years; age range, 25-65 years] [five men; mean age, 46 years; age range, 29-61 years]). All patients had previously undergone spine MRI, conventional dynamic myelography, and CT myelography. Subsequent dynamic CT myelography covered a mean range of seven vertebral levels. The leak was caused by a calcified microspur in 10 patients and by a dural tear at the axilla of a spinal nerve root in the remaining four. The mean volume CT dose index of dynamic CT myelography was 107 mGy (range, 12-246 mGy), and the mean dose-length product was 1347 mGy·cm (range, 550-3750 mGy·cm). Conclusion Dynamic CT myelography is a valuable adjunctive tool with which to identify the precise location of a dural tear when other examinations are unsuccessful. © RSNA, 2018 See also the editorial by Dillon in this issue.

Disc herniation, occult on preoperative imaging but visualized microsurgically, as the cause of idiopathic thoracic spinal cord herniation.

Idiopathic spinal cord herniation (ISCH) through an anterior dural defect is rare and the cause is uncertain. Recently, through interpreting imaging studies, disc herniation was proposed to be a major cause for ISCH. We describe the case of a 50-year-old woman with progressive myelopathy who was diagnosed with a thoracic spinal cord herniation. Microsurgical exploration revealed an anterior vertical dural defect and a small concomitant disc herniation, occult on the preoperative imaging, which caused the dural defect and led to ISCH. This intraoperative finding corroborates the emerging notion that disc herniation is the underlying cause of ISCH.

[Competence Based Catalogue of Learning Objectives for Rehabilitation, Physical Medicine, Naturopathic Treatment - Revised Version - Joint Recommendations of the German Society of Rehabilitation Science and the German Society of Physical Medicine and Rehabilitation]. / Kompetenzbasierter Lernzielkatalog "Rehabilitation, Physikalische Medizin, Naturheilverfahren" (RPMN) ­ revidierte Fassung.

Since the first publication of learning objectives for the interdisciplinary subject "Rehabilitation, Physical Medicine, Naturopathic Treatment" in undergraduate medical education in 2004 a revision is reasonable due to heterogenous teaching programmes in the faculties and the introduction of the National Competence Based Catalogue of Learning Objectives in Medicine as well as the "Masterplan Medical Education 2020". Therefore the German Society of Rehabilitation Science and the German Society of Physical Medicine and Rehabilitation started a structured consensus process using the DELPHI-method to reduce the learning objectives and arrange them more clearly. Objectives of particular significance are emphasised. All learning objectives are assigned to the cognitive and methodological level 1 or to the action level 2. The learning objectives refer to the less detailed National Competence Based Catalogue of Learning Objectives in Medicine. The revised learning objectives will contribute to further progress in competence based and more homogenous medical teaching in core objectives of Rehabilitation, Physical Medicine, and Naturopathic Treatment in the faculties.

Management of spontaneous intracranial hypotension - Transorbital ultrasound as discriminator.

OBJECTIVE: Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position. METHODS: Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls. RESULTS: In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91 mm) or without OH (5.48±0.89 mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99 mm) and without OH (5.53±0.99 mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (-0.53±0.34 mm) than in SIH patients without OH (0.05±0.41 mm; p≤0.001) or in control subjects (0.01±0.38 mm; p≤0.001; area under the curve: 0.874 in receiver operating characteristics analysis). CONCLUSIONS: Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH.

Mortality, cancer, and comorbidities associated with chronic pancreatitis: a Danish nationwide matched-cohort study.

BACKGROUND & AIMS: We aimed to assess the risk of death, cancer, and comorbidities among patients with alcoholic and nonalcoholic chronic pancreatitis (CP). METHODS: We performed a nationwide retrospective cohort study, collecting data from Danish registries from 1995 through 2010. We evaluated the prevalences and incidences of death, cancers, and comorbidities among subjects with CP (cases) compared with age- and sex-matched individuals (controls). In total, 11,972 cases (71,814 person-years) and 119,720 controls (917,436 person-years) were included in the analysis. Hazard ratios (HR) were estimated by Cox proportional hazards regression. RESULTS: Forty-six percent of the cases died during the follow-up period, compared with 13.0% of controls (mean age, 63.7 vs 72.1 y; P < .0001), corresponding to a HR of 5.0 for CP (95% confidence interval [CI], 4.8-5.2). Cancer was a frequent cause of death among cases (10.2%) and controls (3.3%). Cancer (particularly pancreatic cancer) was a frequent cause of death among cases; the HR was 6.9 (95% CI, 7.5-11.8). Alcoholic CP did not produce a higher risk for cancer or death than nonalcoholic CP. Cerebrovascular disease (HR, 1.3; 95% CI, 1.2-1.4), chronic pulmonary disease (HR, 1.9; 95% CI, 1.8-2.1), ulcer disease (HR, 3.6; 95% CI, 3.3-3.9), diabetes (HR, 5.2; 95% CI, 5.0-5.6), and chronic renal disease (HR, 1.7; 95% CI, 1.5-1.9) occurred more frequently among patients with CP, but myocardial infarction did not (HR, 0.9; 95% CI, 0.8-1.0). CONCLUSIONS: Based on a Danish nationwide cohort study, individuals with CP are at higher risk for death from cancer (particularly pancreatic cancer) and have a higher incidence of comorbidities than people without CP.

The risk of fractures among patients with cirrhosis or chronic pancreatitis.

BACKGROUND & AIMS: Cirrhosis and chronic pancreatitis (CP) are accompanied by inflammation and malnutrition. Both conditions can have negative effects on bone metabolism and promote fractures. We evaluated the risk of fractures among patients with CP or cirrhosis and determined the effect of fat malabsorption on fracture risk among patients with CP. METHODS: We performed a retrospective cohort study using the Danish National Patient Register to identify patients diagnosed with CP or cirrhosis. We analyzed data collected from January 1, 1995, to December 31, 2010, on 20,769 patients (35.5% women with cirrhosis and 11,972 patients (33.5% women) with CP. Each patient was compared with 10 age- and sex-matched controls. We also assessed the risk of fractures among patients with CP who received pancreatic enzyme substitution (PES) for fat malabsorption. RESULTS: During the study period, bone fractures occurred in 3954 patients with cirrhosis and 2594 patients with CP. The adjusted hazard ratio (HR) for any fracture was 2.4 in patients with cirrhosis (95% confidence interval [CI], 2.2-2.5) and 1.7 in patients with CP (95% CI, 1.6-1.8). The relative risk of low-trauma fractures was highest among individuals younger than 50 years old. Alcohol as an etiology was associated with an increased risk of fracture compared with patients with nonalcoholic cirrhosis (HR, 2.4 vs 1.5; P < .0001) and CP (HR, 2.0 vs 1.5; P < .0001). Patients with CP receiving PES for fat malabsorption had a lower risk of fractures than other CP patients (HR, 0.8; 95% CI, 0.7-0.9). However, increasing the duration of treatment with PES was associated with an increased risk of fracture. CONCLUSIONS: Patients, especially younger patients, with cirrhosis or CP have an increased risk of fractures of all types.

[Necessary or unnecessary? a critical glance on spine surgery]. / Nötig oder unnötig? Rückenoperationen im kritischen Blick.

Patients with complaints and symptoms caused by spinal degenerative diseases demonstrate a high rate of spontaneous improvement. Except of severe neurological symptoms such as high grade motor deficits, medically intractable pain and vegetative symptoms (cauda syndrome) operations require 1) symptoms, 2) a mechanical cause visible on imaging that sufficiently explains the symptoms, 3) a completed conservative treatment protocol performed over a 4) 6-12 week period. According to the evidence found in the literature, patients with lumbar disk herniation significantly benefit from surgery by a faster relieve of pain and return to social and professional activity, however, the results are converging after a period of 1-2 years. Surgery of lumbar spinal stenosis is considered a gold standard and superior to conservative care when symptoms are severe and leg pain is present. Bilateral microsurgical decompression using a bilateral or a unilateral approach with over-the-top decompression of the contralateral nerve root are superior to laminectomy as the decompression procedure. Lumbar fusion is only indicated in patients with spinal stenosis when a major or mobile spondylolisthesis is diagnosed. There is no indication of prophylactic surgery to avoid a "dangerous" deficit that might develop in the future.

Patient-reported symptomatology and its course in spontaneous intracranial hypotension - Beware of a chameleon.

OBJECTIVE: Although orthostatic headache is the hallmark symptom of spontaneous intracranial hypotension (SIH), patients can present with a wide range of different complaints and thereby pose a diagnostic challenge for clinicians. Our aim was to describe and group the different symptoms associated with SIH and their course over time. METHODS: We retrospectively surveyed consecutive patients diagnosed and treated for SIH at our institution from January 2013 to May 2020 with a specifically designed questionnaire to find out about their symptomatology and its course. RESULTS: Of 112 eligible patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 67 (84.8%) reported initial orthostatic headaches, whereas 12 (15.2%) denied having this initial symptom. All except one (98.7%) patients reported additional symptoms: most frequently cephalic pressure (69.6%), neck pain (68.4%), auditory disturbances (59.5%), nausea (57%), visual disturbances (40.5%), gait disturbance (20.3%), confusion (10.1%) or sensorimotor deficits (21.5%). Fifty-seven (72.2%) patients reported a development of the initial symptoms predominantly in the first three months after symptom onset. Age and sex were not associated with the symptomatology or its course (p > 0.1). CONCLUSION: Although characteristic of SIH, a relevant amount of patients present without orthostatic headaches. In addition, SIH can manifest with non-orthostatic headaches at disease onset or during the course of the disease. Most patients report a wide range of associated complaints. A high degree of suspicion is crucial for an early diagnosis and targeted treatment.

Combined dielectrophoresis-Raman setup for the classification of pathogens recovered from the urinary tract.

Rapid and effective methods of pathogen identifications are of major interest in clinical microbiological analysis to administer timely tailored antibiotic therapy. Raman spectroscopy as a label-free, culture-independent optical method is suitable to identify even single bacteria. However, the low bacteria concentration in body fluids makes it difficult to detect their characteristic molecular fingerprint directly in suspension. Therefore, in this study, Raman spectroscopy is combined with dielectrophoresis, which enables the direct translational manipulation of bacteria in suspensions with spatial nonuniform electrical fields so as to perform specific Raman spectroscopic characterization. A quadrupole electrode design is used to capture bacteria directly from fluids in well-defined microsized regions. With live/dead fluorescence viability staining, it is verified, that the bacteria survive this procedure for the relevant range of field strengths. The dielectrophoretic enrichment of bacteria allows for obtaining high quality Raman spectra in dilute suspensions with an integration time of only one second. As proof-of-principle study, the setup was tested with Escherichia coli and Enterococcus faecalis, two bacterial strains that are commonly encountered in urinary tract infections. Furthermore, to verify the potential for dealing with real world samples, pathogens from patients' urine have been analyzed. With the additional help of multivariate statistical analysis, a robust classification model could be built and allowed the classification of those two strains within a few minutes. In contrast, the standard microbiological diagnostics are based on very time-consuming cultivation tests. This setup holds the potential to reduce the crucial parameter diagnosis time by orders of magnitude.

Idiopathic Ventral Spinal Cord Hernia-A Single-Center Case Series of 11 Patients.

BACKGROUND: Idiopathic spinal cord herniations (ISCH) are rare defects of the ventromedial or mediolateral dura mater with herniation of the spinal cord through the defect with approximately 350 described cases worldwide. Patients usually become symptomatic with motor or sensory neurological deficits and gait disturbances. OBJECTIVE: To describe characteristic symptoms and clinical findings and to evaluate the postoperative course and outcomes of ISCH. METHODS: We present a single-center data analysis of a case series of 11 consecutive patients who were diagnosed with ISCH and underwent surgery in our department between 2009 and 2021. RESULTS: All herniations were located in the thoracic spine between T2 and T9. In most cases, gait ataxia and dysesthesia led to further workup and subsequently to the diagnosis of ISCH. A "far-enough" posterior-lateral surgical approach, hemilaminectomy or laminectomy with a transdural approach, was performed under intraoperative neurophysiological monitoring which was followed by adhesiolysis, repositioning of the spinal cord and sealing using a dura patch. After surgery, clinical symptoms improved in 9 of 11 patients (81.8%), while only 1 patient experienced deterioration of symptoms (9.1%) and 1 patient remained equal (9.1%). The median preoperative McCormick grade was 3 (±0.70), while the median postoperative grade was 2 (±0.98) ( P = .0047). CONCLUSION: In our case series of ISCH, we found that in most patients, neurological deficits improved postoperatively. This indicates that surgery in ISCH should not be delayed in symptomatic patients.

The Contralateral Approach to intra- and Extraforaminal Lumbar Disk Herniations: Surgical Technique and Review of Surgical Procedures.

BACKGROUND: Surgery for intra-/extraforaminal disk herniations (IEDH) is technically demanding due to the hidden location of the compressed nerve root section. Ipsilateral approaches (medial and lateral) are accompanied by extended resection of the facet joint and inadequate visualization of the pathology, especially at the L5-S1 level. METHODS: We describe a microsurgical interlaminar contralateral approach (MICA) suitable for IEDH at the lumbosacral junction that can also be used at L4-L5 and L3-L4. CONCLUSION: The MICA provides access and sufficient intraforaminal visualization for IEDH in the lumbosacral region without resection of stability-relevant structures or manipulation of the nerve root ganglion.

Safety and efficacy of stand-alone anterior lumbar interbody fusion in low-grade L5-S1 isthmic spondylolisthesis.

Introduction: Surgical management of isthmic spondylolisthesis is controversial and reports on anterior approaches in the literature are scarce. Research question: To evaluate the safety and efficacy of stand-alone anterior lumbar interbody fusion (ALIF) in patients with symptomatic low-grade L5-S1 isthmic spondylolisthesis. Material and methods: All adult patients with isthmic spondylolisthesis of the lumbosacral junction treated in a single institution between 2008 and 2019 with stand-alone ALIF were screened. A titan cage was inserted at L5-S1 with vertebral anchoring screws. Prospectively collected surgical, clinical and radiographic data were analyzed retrospectively. Results: 34 patients (19 men, 15 women, mean age 52.5 â€‹± â€‹11.5 years) with a mean follow-up of 3.2 (±2.5) years were analyzed. 91.2% (n â€‹= â€‹31) of patients had a low-grade spondylolisthesis and 8.8% (n â€‹= â€‹3) grade III according to Meyerding classification. Mean COMI and ODI scores improved significantly from 6.9 (±1.5) and 35.5 (±13.0) to 2.0 (±2.5) and 10.2 (±13.0), respectively after one year, and to 1.7 (±2.5) and 8.2 (±9.6), respectively, after two years. The COMI and ODI scores improved in 86.4% and 80%, respectively, after one year and 92.9% of patients after two years by at least the minimal clinically important difference. No intraoperative complications were recorded. 8.8% (n â€‹= â€‹3) of patients needed a reoperation. Discussion and conclusion: After stand-alone ALIF for symptomatic isthmic spondylolisthesis, the patients improved clinically important after one and two years. Stand-alone ALIF is a safe and effective surgical treatment option for low-grade isthmic spondylolisthesis.

A standardized model for in vitro testing of sutures and patches for watertight dural closure.

OBJECTIVE: CSF leaks are common complications of spinal and cranial surgeries. Several dural grafts and suture techniques are available to achieve watertight dural closure, but the effectiveness of these techniques remains unclear. The authors developed a standardized in vitro model to test available grafts and suture techniques alone or in combination to find the technique with the most watertight dural closure. METHODS: A fluid chamber with a dural fixation device, infusion pump, pressure gauge, and porcine pericardium as a dural equivalent was assembled to provide the reusable device for testing. The authors performed dural closure in 4 different fashions, as follows: A) using running versus simple interrupted suture technique and different suture materials to close a 3-cm incision; B) selecting commonly used sealants and dural patches in combination with a running suture; C) performing duraplasty (1.5 × 1.5-cm square defect) with different dural substitutes in a stand-alone fashion; and D) performing duraplasty with different dural substitutes in a double-layer fashion. Each technique was tested 6 times. The hydrostatic burst pressure (BP) was measured and compared using the Kruskal-Wallis test or the Mann-Whitney U-test. Values are reported as mean ± SD. RESULTS: There was no significant difference between the running and simple interrupted suture technique (p = 0.79). Adding a patch or sealant to a suture resulted in a 1.7- to 14-fold higher BP compared to solitary suture closure (36.2 ± 24.27 cm H2O and 4.58 ± 1.41 cm H2O, respectively; p < 0.001). The highest BP was achieved by adding DuraSeal or TachoSil (82.33 ± 12.72 cm H2O and 74.17 ± 12.64 cm H2O, respectively). For closing a square defect, using a double-layer duraplasty significantly increased BP by a factor of 4-12 compared to a single-layer duraplasty (31.71 ± 12.62 cm H2O vs 4.19 ± 0.88 cm H2O, respectively; p < 0.001). The highest BP was achieved with the combination of Lyomesh and TachoSil (43.67 ± 11.45 cm H2O). CONCLUSIONS: A standardized in vitro model helps to objectify the watertightness of dural closure. It allows testing of sutures and dural grafts alone or in combination. In the authors' testing, a running 6-0 monofilament polypropylene suture combined with DuraSeal or TachoSil was the technique achieving the highest BP. For the duraplasty of square defects, the double-layer technique showed the highest efficacy.

Outcome after surgical treatment of cerebrospinal fluid leaks in spontaneous intracranial hypotension-a matter of time.

OBJECTIVE: Spinal cerebrospinal fluid (CSF) leaks cause spontaneous intracranial hypotension (SIH). Microsurgery can sufficiently seal spinal CSF leaks. Yet, some patients suffer from residual symptoms. Aim of the study was to assess predictors for favorable outcome after surgical treatment of SIH. METHODS: We included consecutive patients with SIH treated surgically from January 2013 to May 2020. Subjects were surveyed by a questionnaire. Primary outcome was resolution of symptoms as rated by the patient. Secondary outcome was postoperative headache intensity on the numeric rating scale (NRS). Association between variables and outcome was assessed using univariate and multivariate regression. A cut-off value for continuous variables was calculated by a ROC analysis. RESULTS: Sixty-nine out of 86 patients (80.2%) returned the questionnaire and were analyzed. Mean age was 46.7 years and 68.1% were female. A significant association with the primary and secondary outcome was found only for preoperative symptom duration (p = 0.001 and p < 0.001), whereby a shorter symptom duration was associated with a better outcome. Symptom duration remained a significant predictor in a multivariate model (p = 0.013). Neither sex, age, type of pathology, lumbar opening pressure, nor initial presentation were associated with the primary outcome. ROC analysis yielded treatment within 12 weeks as a cut-off for better outcome. CONCLUSION: Shorter duration of preoperative symptoms is the most powerful predictor of favorable outcome after surgical treatment of SIH. While an initial attempt of conservative treatment is justified, we advocate early definitive treatment within 12 weeks in case of persisting symptoms.