[Postdural puncture headache after neuraxial anesthesia: incidence and risk factors]

Hintergrund/Ziel der Arbeit

Der postpunktionelle Kopfschmerz (PKS) ist eine Komplikation nach rückenmarknahen Verfahren (RA) mit erheblichem Krankheitswert. Ziel der Untersuchung war es, die Inzidenz des PKS in 2 großen operativen Kollektiven zu untersuchen, mögliche Risikofaktoren zu identifizieren und den Einfluss auf die Krankenhausverweildauer zu untersuchen.

Material und Methoden

In einer retrospektiven Analyse des Zeitraums 2010–2012 wurden 341 unfallchirurgische (UCH) und 2113 geburtsmedizinische (GEB) Patient*innen nach Spinalanästhesie (SPA) analysiert. In der statistischen Auswertung (SPSS-23) kamen univariate Analysen mittels Mann-Whitney-U-, Chi²- und Student’s t‑Test sowie logistische Regressionsanalysen zur Anwendung.

Ergebnisse

Die Inzidenz des PKS betrug in der UCH-Gruppe 5,9 % und in der GEB-Gruppe 1,8 %. Patient*innen mit PKS in der UCH wiesen ein jüngeres Patientenalter (38 vs. 47 Jahre, p = 0,011), einen geringeren BMI (23,5 vs. 25,2, p = 0,037) sowie ein niedrigeres Köpergewicht (70,5 kg vs. 77 kg, p = 0,006) als Patient*innen ohne PKS auf. Dabei konnten das Alter mit einer „odds ratio“ (OR 97,5 % Konfidenzintervall [KI]) von 0,963 (97,5% KI 0,932–0,991, p = 0,015) und das Köpergewicht mit einer OR von 0,956 (97,5 % KI 0,920–0,989, p = 0,014) als unabhängige Risikofaktoren für die Entstehung eines PKS identifiziert werden. In der GEB wies die SPA eine höhere Inzidenz des PKS auf als die kombinierte Spinalepiduralanästhesie (CSE) (8,6 % vs. 1,2 %, p < 0,001). Dabei erwies sich das Verfahren mit einer OR von 0,049 (97,5 % KI 0,023–0,106, p < 0,001) als unabhängiger Risikofaktor für die Entstehung eines PKS. In beiden Gruppen war der PKS mit einem verlängerten Krankenhausaufenthalt assoziiert (UCH-Gruppe 4 vs. 2 Tage, p = 0,001; GEB-Gruppe 6 vs. 4 Tage, p < 0.0005).

Diskussion

Die Inzidenz des PKS nach SPA/CSE war in unserer Untersuchung in den beschriebenen Patientengruppen unterschiedlich, mit einem deutlich höheren Anteil in der UCH-Gruppe. Alter, Konstitution und Verfahren waren hinweisgebende Risikofaktoren eines PKS. In Anbetracht der funktionellen Einschränkungen (Mobilisation, Versorgung des Neugeborenen) und des verlängerten Krankenhausaufenthalts, sollten zukünftige Studien eine frühe Behandlung des PKS untersuchen.

Impact of brief prewarming on anesthesia-related core-temperature drop, hemodynamics, microperfusion and postoperative ventilation in cytoreductive surgery of ovarian cancer: a randomized trial

Background

General (GA)- and epidural-anesthesia may cause a drop in body-core-temperature (BCT_drop), and hypothermia, which may alter tissue oxygenation (StO₂) and microperfusion after cytoreductive surgery for ovarian cancer. Cell metabolism of subcutaneous fat- or skeletal muscle cells, measured in microdialysis, may be affected. We hypothesized that forced-air prewarming during epidural catheter placement and induction of GA maintains normothermia and improves microperfusion.

Methods

After ethics approval 47 women scheduled for cytoreductive surgery were prospectively enrolled. Women in the study group were treated with a prewarming of 43 °C during epidural catheter placement. BCT (Spot on®, 3 M) was measured before (T₁), after induction of GA (T₂) at 15 min (T₃) after start of surgery, and until 2 h after ICU admission (T_ICU2h). Primary endpoint was BCT_drop between T₁ and T₂. Microperfusion-, hemodynamic- and clinical outcomes were defined as secondary outcomes. Statistical analysis used the Mann-Whitney-U- and non-parametric-longitudinal tests.

Results

BCT_drop was 0.35 °C with prewarming and 0.9 °C without prewarming (p < 0.005) and BCT remained higher over the observation period (ΔT₄ = 0.9 °C up to ΔT₇ = 0.95 °C, p < 0.001). No significant differences in hemodynamic parameters, transfusion, arterial lactate and dCO₂ were measured. In microdialysis the ethanol ratio was temporarily, but not significantly, reduced after prewarming. Lactate, glucose and glycerol after PW tended to be more constant over the entire period. Postoperatively, six women without prewarming, but none after prewarming were mechanical ventilated (p < 0.001).

Conclusion

Prewarming at 43 °C reduces the BCT_drop and maintains normothermia without impeding the perioperative routine patient flow. Microdialysis indicate better preserved parameters of microperfusion.

Trial registration

ClinicalTrials.gov; ID: NCT02364219; Date of registration: 18-febr-2015.

Positional venous MR angiography: an operator-independent tool to evaluate cerebral venous outflow hemodynamics

BACKGROUND AND PURPOSE

CCSVI has been proposed as a cause for MS. According to this theory, strictures of the IJV are among the described causes for CCSVI. Little is known about their influence on the hemodynamics of the CVBO. We used positional MR imaging to describe the influence of positional changes on the CVBO.

MATERIALS AND METHODS

Using the Fonar Upright MR imaging system, we performed venous time-of-flight angiography of the cervical region in the supine and sitting positions in 15 healthy volunteers. The image quality was rated; the positional findings and interindividual variances in the CVBO were analyzed.

RESULTS

A venous time-of-flight angiography of the cervical spine was feasible with good image quality. Strictures of 1 or both IJVs were found in 8 of 15 healthy volunteers in the supine position; however, none were visible in upright position. The IJV was not the main outflow route in the erect position. No relevant venous reflux was observed.

CONCLUSIONS

IJV strictures are a common finding in healthy volunteers in the supine position. They seem to be of no relevance in the erect position. This finding questions the validity of this criterion for the diagnosis of CCSVI. Reflux into the venous system was not visualized, and it remains to be seen whether it can be identified in patients with MS. Positional MR imaging enables operator-independent evaluation of the CVBO and may help to clarify the validity of the criteria for CCSVI.

Spondylolysis and isthmic spondylolisthesis: impact of vertebral hypoplasia on the use of the Meyerding classification

BACKGROUND

Spondylolysis and isthmic spondylolisthesis are common multifactorial disorders. The extent of slipping of the spondylolytic vertebra is considered a major predicator for prognosis and further follow-up. Vertebral hypoplasia is a common finding associated with spondylolysis. The purpose of this study is to evaluate the incidence of hypoplastic vertebral bodies in patients with spondylolysis and in the general population and to analyse the impact of the findings on the measurement and grading of spondylolisthesis.

METHODS

140 patients with 141 levels of spondylolysis identified by MRI were included in this study. The slippage of the spondylolytic vertebral body and the size in the midline sagittal image were measured and correlated. In addition, a randomised control group was evaluated to test the hypothesis that shortened, hypoplastic vertebral bodies can also be found in the general population.

RESULTS

Shortened, hypoplastic vertebrae were found in 50 patients with spondylolysis and none was found in the control group. These shortened vertebrae mimicked spondylolisthesis and in 19 patients the slippage equalled the shortening, thus mimicking spondylolisthesis, although only spondylolysis was present.

CONCLUSION

Sagittal shortening of the spondylolytic vertebra is common and may mimic spondylolisthesis. In order to define and measure spondylolisthesis the shortening of the spondylolytic vertebra has to be taken into account.

Features of positional magnetic resonance imaging in tethered cord syndrome

PURPOSE

Tethered cord syndrome (TCS) is a clinical entity in which symptoms are induced through excessive tension on the spinal cord. The radiological method of choice to confirm TCS is magnetic resonance imaging (MRI), however limitations exist especially in patients with no underlying spinal dysraphism.

MATERIALS AND METHODS

The positional MRI features of TCS in a series of four patients with suspected or proven TCS are described, especially with respect to contact of the myelon or the cauda equina with the dorsal elements of the lumbar spinal canal. The findings are correlated with the lordosis angle of the lumbar spine.

RESULTS

In flexion contact of the myelon or the cauda equina with the dorsal elements of the lumbar spinal canal is reduced due to a straightening of the lumbar spine. With increasing lordosis of the lumbar spine, the degree of contact increases and detection of TCS is more difficult. The site of tethering could be identified in all four patients in flexion.

CONCLUSION

Positional MRI can be useful to confirm or rule out TCS and helpful to identify the site of tethering. The value of positional MRI is limited to patients who are able to fully flex the lumbar spine and in patients without spinal canal stenosis and spondylolisthesis.

[Pathomechanisms of spinal canal stenosis - upright MRI image gallery]

AIM

Lumbar spinal canal stenosis is a common disease of the elderly patient, with a high prevalence and clinical importance. MRI is the established method of choice for the imaging of spinal canal stenosis. However, there is often a discrepancy between the clinical symptoms and the spinal canal stenosis as shown using MRI in a supine position. In such cases preoperative functional imaging is often warranted.

METHODS

In an image gallery three cases of a functional spinal canal stenosis of the lumbar spine are shown. In all three patients a dynamic, positional MRI (upright MRI) was performed.

RESULTS

The pathomechanisms of the spinal canal stenosis could be shown in all three cases.

CONCLUSION

Using upright MRI a functional spinal canal stenosis can be shown. The pathomechanisms of the spinal canal stenosis are discussed. The possibilities and limitations of this new imaging modality are presented and analysed.

Spondylolisthesis and posterior instability

We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.

Magnetic versus manual guidewire manipulation in neuroradiology: in vitro results

INTRODUCTION

Standard microguidewires used in interventional neuroradiology have a predefined shape of the tip that cannot be changed while the guidewire is in the vessel. We evaluated a novel magnetic navigation system (MNS) that generates a magnetic field to control the deflection of a microguidewire that can be used to reshape the guidewire tip in vivo without removing the wire from the body, thereby potentially facilitating navigation along tortuous paths or multiple acute curves.

METHOD

The MNS consists of two permanent magnets positioned on either side of the fluoroscopy table that create a constant precisely controlled magnetic field in the defined region of interest. This field enables omnidirectional rotation of a 0.014-inch magnetic microguidewire (MG). Speed of navigation, accuracy in a tortuous vessel anatomy and the potential for navigating into in vitro aneurysms were tested by four investigators with differing experience in neurointervention and compared to navigation with a standard, manually controlled microguidewire (SG).

RESULTS

Navigation using MG was faster (P=0.0056) and more accurate (0.2 mistakes per trial vs. 2.6 mistakes per trial) only in less-experienced investigators. There were no statistically significant differences between the MG and the SG in the hands of experienced investigators. One aneurysm with an acute angulation from the carrier vessel could be navigated only with the MG while the SG failed, even after multiple reshaping manoeuvres.

CONCLUSION

Our findings suggest that magnetic navigation seems to be easier, more accurate and faster in the hands of less-experienced investigators. We consider that the features of the MNS may improve the efficacy and safety of challenging neurointerventional procedures.

Fifteen-year follow-up of a patient with beta thalassaemia and extramedullary haematopoietic tissue compressing the spinal cord

A long-term follow-up of a patient with beta thalassaemia with intra- and extraspinal extramedullary haematopoietic tissue compressing the spinal cord is presented. Extramedullary haematopoietic nodules are a rare cause of spinal cord compression and should be included in the differential diagnosis, especially in patients from Mediterranean countries. Treatment with radiation therapy solely failed, giving rise to the need of surgical intervention. Surgical decompression of the spine and the removal of the culprit lesion compressing the spine were performed. Postinterventional radiation therapy was applied to the spine. A relapse had to be treated again by surgical means combined with postinterventional radiation therapy. A complete relief of the symptoms and control of the lesion could be obtained.

Venocutaneous fistula

This is the first description of venocutaneous fistula, a late complication of elective laparoscopic cholecystectomy that arose 18 months after the initial operation. Postoperatively, the patient twice developed an abscess in the abdominal wall at the former site of the umbilical trocar. The first abscess occurred on the 6th postoperative day; the second, after 14 months. After an additional 4 months, a fistula opening appeared just below the umbilicus. Fistulography revealed a connection with the venous system of the omentum majus. During subsequent resection of the fistula, a pigment gallstone was retrieved from the base of the fistula.

Peripheral directional atherectomy evaluated with a rotational digital angiography system

BACKGROUND

One of the factors that affect the recurrence rate after peripheral directional atherectomy (DA) is the degree of residual stenosis. A new method of peripheral DA to reduce residual stenoses was evaluated with a rotational digital angiography (RDA) system that provides both angiography and fluoroscopy at multiple projections within 360 degrees.

PATIENTS AND METHODS

Between March 1995 and July 1999, severe short segmental stenoses of six iliac arteries and two superficial femoral arteries (SFA) in eight patients were treated with the Simpson DA catheter under RDA system guidance. After pre-procedural RDA evaluation, the first series of DA were performed under ordinary PA fluoroscopic guidance. The residual stenoses were evaluated with RDA. If the residual stenoses exceeded 30%, a second series of DA were performed covering the residual plaque with the cutter window of the DA catheter. To this purpose the fluoroscopy of the RDA system was fixed in the direction in which the residual stenoses were largest and most eccentric. The end point was defined to be a residual stenosis of less than 30% evaluated with the RDA system, and the procedures were repeated until the end point was achieved.

RESULTS

Five of six iliac artery lesions were curved at the pre-procedural RDA evaluation. After the first series of DA, only two of six iliac lesions but all SFA lesions achieved the end point. Among the four other iliac lesions, three achieved the end point with one or two additional series of DA using the RDA system guidance to control the selective cuts of the residual plaques. One patient had a residual stenosis of 50% because the procedure could not be completed by balloon rupture of the DA catheter. In the patients with iliac stenoses, there was no final residual stenosis in one, and the range was from 20% to 25% in the four patients. The residual stenoses were located on the greater curvature side of the curved artery in three of these four patients.

CONCLUSION

The RDA system is a valuable tool in aiding reduction of the residual stenoses during peripheral DA. Minimal stenoses often remain on the greater curvature side of the wall because the rigid and straight metallic capsule (cylindrical housing) of the Simpson DA catheter does not completely fit the curved wall. This phenomenon was thought to be a mechanical limitation of this device.