Postoperative Pain Trajectories and Pain Chronification-an Empirical Typology of Pain Patients.

Background: High intensity of acute postsurgical pain is one of the strongest predictors of chronic postsurgical pain (CPSP). We investigated if different types of patients with distinct combinations of initial pain intensity and rate of pain resolution exhibit different risks for increased pain intensity six months after surgery. Methods: Data from 174 patients were examined using growth mixture analysis by means of structural equation modeling. Results: Three types of patients were distinguished on the basis of acute pain trajectories. The majority of patients (57%) showed an unproblematic pattern of little initial pain on the first postoperative day, combined with further pain resolution over the four subsequent days. There also was a substantial group of patients (30%) who started out with severe pain but exhibited a high rate of pain resolution. Finally, we found a problematic group of patients (13%) who reported high pain intensities throughout all five postoperative measurements, with no signs of pain resolution. Even after controlling for preoperative pain intensity, these patients exhibited significantly higher pain intensities six months after surgery than the remaining patient groups. Conclusions: In this study, we demonstrated that there is substantial variation in postsurgical pain trajectories, not only with regard to postsurgical initial pain intensity, but also with regard to individual rates of pain resolution. Successful pain resolution appeared to be a better predictor of absence of increased pain intensities six months after surgery than initial pain immediately after surgery. Hence, attention should be given to appropriate pain treatment in order to minimize the risk of CPSP.

Cage deviation in the subaxial cervical spine in relation to implant position in the sagittal plane.

Subsidence of interbody cages is a frequently observed and relevant complication in anterior cervical discectomy and fusion (ACDF). Only a handful of studies concentrated on the modality of subsidence and its clinical impact. We performed a retrospective analysis of ACDF patients from 2004 to 2010. Numeric analog scale (NAS) score pre-op and post-op, Oswestry Disability Index (ODI) on x-rays, endplate (EP) and cage dimensions, implant position, lordotic/kyphotic subsidence patterns (>5°), and cervical alignment were recorded. Subsidence was defined as height loss >40%. Patients were grouped into single segment (SS), double segment (DS), and plated procedures. We included 214 patients. Prevalence of subsidence was 44.9% overall, 40.9% for SS, and 54.8% for DS. Subsidence presented mostly for dorsal (40.7%) and mid-endplate position (46.3%, p < 0.01); dorsal placement resulted in kyphotic (73.7%) and central placement in balanced implant migration (53.3%, p < 0.01). Larger cages (>65% EP) showed less subsidence (64.6 vs. 35.4%, p < 0.01). There was no impact of subsidence on ODI or alignment. NAS was better for subsided implants in SS (p = 0.06). Cages should be placed at the anterior endplate rim in order to reduce the risk of subsidence. Spacers should be adequately sized for the respective segment measuring at least 65% of the segment dimensions. The cage frame should not rest on the vulnerable central endplate. For multilevel surgery, ventral plating may be beneficial regarding construct stability. The reduction of micro-instability or over-distraction may explain lower NAS for subsided implants.

Safety and efficacy of gravitational shunt valves in patients with idiopathic normal pressure hydrocephalus: a pragmatic, randomised, open label, multicentre trial (SVASONA).

OBJECTIVES: To investigate whether gravitational valves reduce the risk of overdrainage complications compared with programmable valves in ventriculoperitoneal (VP) shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). BACKGROUND: Patients with iNPH may benefit from VP shunting but are prone to overdrainage complications during posture changes. Gravitational valves with tantalum balls are considered to reduce the risk of overdrainage but their clinical effectiveness is unclear. METHODS: We conducted a pragmatic, randomised, multicentre trial comparing gravitational with non-gravitational programmable valves in patients with iNPH eligible for VP shunting. The primary endpoint was any clinical or radiological sign (headache, nausea, vomiting, subdural effusion or slit ventricle) of overdrainage 6 months after randomisation. We also assessed disease specific instruments (Black and Kiefer Scale) and Physical and Mental Component Scores of the Short Form 12 (SF-12) generic health questionnaire. RESULTS: We enrolled 145 patients (mean (SD) age 71.9 (6.9) years), 137 of whom were available for endpoint analysis. After 6 months, 29 patients in the standard and five patients in the gravitational shunt group developed overdrainage (risk difference -36%, 95% CI -49% to -23%; p<0.001). This difference exceeded predetermined stopping rules and resulted in premature discontinuation of patient recruitment. Disease specific outcome scales did not differ between the groups although there was a significant advantage of the gravitational device in the SF-12 Mental Component Scores at the 6 and 12 month visits. CONCLUSIONS: Implanting a gravitational rather than another type of valve will avoid one additional overdrainage complication in about every third patient undergoing VP shunting for iNPH.

On the method of a randomised comparison of programmable valves with and without gravitational units: the SVASONA study.

OBJECTIVE: The supremacy of low-pressure valves (LPV) in the therapy of patients with idiopathic normal pressure hydrocephalus (iNPH) has been proven by the Dutch NPH study. The downside of LPVs is the high rate of overdrainage complications. In the meantime gravitational units have been developed with the objective of minimising overdrainage complications. Do these gravitational units allow the same favourable outcomes as in the Dutch NPH study without overdrainage complications? The goal of this prospective randomised controlled multicentre trial is to compare the rate of overdrainage complications after shunt surgery with programmable valves with or without a gravitational unit. METHOD: Patients suspected with iNPH with gait ataxia and one or two other symptoms of Hakim's triad and enlarged ventricles on CT or MRI underwent a cerebrospinal fluid (CSF) infusion test, CSF tap test and/or continuous ICP measurement in seven experienced centres. If iNPH was diagnosed the patients were randomised to receive a ventriculoperitoneal shunt with a programmable valve with or without a gravitational unit. The patients were followed up for 3, 6 and 12 months after surgery. The primary hypothesis of the study was that programmable valves with gravitational units will reduce the rate of overdrainage from 25% to 10%. The outcome measured by iNPH-specific outcome scales (Kiefer score, Black grading scale) and the generic quality of life (short form 12, SF12) was defined as the secondary endpoint. To detect the hypothesised difference in the incidence of overdrainage with a type I error of 5% and a type II error of 20%, correcting for multiple testing and an anticipated drop-out rate of 10%, we planned to enrol 250 patients. To ensure safety and efficacy we performed a planned interim analysis halfway. RESULTS: The study design has been found to be effective with regard to the primary hypothesis. CONCLUSION: The design of the SVASONA study was developed to be able to confirm the primary hypothesis. Thus, the method of the study should solve the dilemma of the Dutch NPH study by the randomised comparison of LPVs with and without gravitational units.

Retrospective Matched-Pair Cohort Study on Effect of Bisegmental Fenestration versus Hemilaminectomy for Bisegmental Spinal Canal Stenosis at L3-L4 and L4-L5.

Background The main symptoms of degenerative lumbar spinal canal stenosis are progressive back pain, spinal claudication, and, occasionally, sensory and motor deficits. Impairments particularly occur during walking, standing, and sitting. Thus social and vocational activities are increasingly restricted, causing considerable suffering for patients. Surgical therapies are superior to conservative ones. This article studies the outcome of 2-level fenestration versus hemilaminectomy for bisegmental spinal stenosis decompression. Methods This retrospective matched-pair cohort study included a total of 144 patients who underwent surgery for bisegmental spinal stenosis at the levels L3-4 and L4-5 between 2008 and 2012. There were 72 matching pairs that corresponded in sex, year of birth, and width of the stenosed segments. The patients' impairments were reported before, immediately after, and 6 and 12 months after surgery using the Oswestry Disability Questionnaire (ODQ-D) and the EuroQol-5D (EQ-5D). The data were evaluated statistically. Results The comparison of both surgical procedures regarding walking ability (walking a distance with and without a walking aid) revealed a significant difference. Patients who underwent hemilaminectomy had better postoperative results. The individual criteria of the ODQ-D and EQ-5D revealed no significant differences between 2-level fenestration and hemilaminectomy; however, there is always significant postoperative improvement in comparison with preoperative status. Age, sex, body mass index, comorbidities, smoking, and alcohol consumption had no influence on the surgical results. The reoperation rate was between 13% and 15% for both surgical techniques, not being significantly different. Conclusion Fenestration and hemilaminectomy are equivalent therapies for bisegmental lumbar spinal canal stenosis. Regarding walking, the study revealed better results for hemilaminectomy than for fenestration in this cohort of patients. Pain intensity, personal care, lifting and carrying of objects, sitting, social life, and travel all improved significantly postoperatively as compared with preoperatively. In both groups, health status as the decisive predictor improved considerably after surgery. We could show that both surgical methods result in significant postoperative improvement of all the individual criteria of the ODQ-D and the EQ-5D.

How Many Cases of Spine Surgery Are Performed in Germany? Method of Counting the Number of Cases of Spine Surgery in Germany.

Objective The number of cases of spinal DRGs (German Diagnosis-Related Groups) is calculated on the basis of the data released by the German DRG-Institute. The data thus obtained were subsequently compared with the previously publicly debated data of cases, which were based on the counting of OPS (German Procedure Classification) codes. Methods Specific and Nonspecific Spinal DRGs are identified according to the German Coding Guidelines and the OPS catalogs. Those are verified in a multistage process, including the formation of test cases, to ensure that those DRGs consistently contain spinal cases. The verified DRGs are filtered out of the G-DRG § 21 KHEntgG Browser, including the years from 2005 to 2012 to calculate the respective number of cases. For a better overview, the DRGs are divided into groups according to Specific and Nonspecific Spinal DRGs. Both groups are summarized under the title Surgical Spine DRGs to be able to compare the results with the data already published. Two datasets are used for comparison: one from a publication in the German Ärzteblatt, which is based on the data collected by the German insurance company AOK, and the other from data published by the German Federal Office of Statistics. Results As a result, the number of cases which is presented here shows a significant variance compared with the figures that have been published. The Specific Spinal DRGs show a growth of 75% from 2005 to 2011. The case numbers of the Nonspecific Spinal DRGs show an increased rate of 51% between 2005 and 2006. In addition, the Surgical Spine DRGs rose by 69% between 2005 and 2011. This contrasts with the German government-proposed increase of 125% in the area of spinal surgery over the same period. Conclusion To summarize, the significant gap between the case numbers presented here and the existing ones gives reason to question the benefit of using OPS codes to calculate the actual number of cases in the field of spinal surgery, and it suggests the advantage of using DRG-based calculations.

Multimodal metabolic imaging of cerebral gliomas: positron emission tomography with [18F]fluoroethyl-L-tyrosine and magnetic resonance spectroscopy.

OBJECT: The purpose of this study was to determine the predictive value of [18F]fluoroethyl-L-tyrosine (FET)-positron emission tomography (PET) and magnetic resonance (MR) spectroscopy for tumor diagnosis in patients with suspected gliomas. METHODS: Both FET-PET and MR spectroscopy analyses were performed in 50 consecutive patients with newly diagnosed intracerebral lesions supposed to be diffuse gliomas on contrast-enhanced MR imaging. Lesion/brain ratios of FET uptake greater than 1.6 were considered positive, that is, indicative of tumor. Results of MR spectroscopy were considered positive when N-acetylaspartate (NAA) was decreased in conjunction with an absolute increase of choline (Cho) and an NAA/Cho ratio of 0.7 or less. An FET lesion/brain ratio, an NAA/Cho ratio, and signal abnormalities on MR images were compared with histological findings in neuronavigated biopsy specimens. The FET lesion/brain ratio and the NAA/Cho ratio were identified as significant independent predictors for the histological identification of tumor tissue. The accuracy in distinguishing neoplastic from nonneoplastic tissue could be increased from 68% with the use of MR imaging alone to 97% with MR imaging in conjunction with FET-PET and MR spectroscopy. Sensitivity and specificity for tumor detection were 100 and 81% for MR spectroscopy and 88 and 88% for FET-PET, respectively. Results of histological studies did not reveal tumor tissue in any of the lesions that were negative on FET-PET and MR spectroscopy. In contrast, a tumor diagnosis was made in 97% of the lesions that were positive with both methods. CONCLUSIONS: In patients with intracerebral lesions supposed to be diffuse gliomas on MR imaging, FET-PET and MR spectroscopy analyses markedly improved the diagnostic efficacy of targeted biopsies.

Endoscope-assisted keyhole surgery via an eyebrow incision for removal of large meningiomas of the anterior and middle cranial fossa.

BACKGROUND: Conventional open surgery of large meningiomas has proven to be challenging even in experienced hands. Intense retraction and dissection around neurovascular structures increase morbidity and mortality. In the present study, we retrospectively analyzed the surgical technique, and outcome in 40 patients with large anterior cranial fossa meningiomas extending to the middle fossa. All patients were approached via a supraorbital mini craniotomy. METHODS: It is a retrospective study of 40 patients (12 males, 28 females) who underwent surgery for large anterior cranial fossa meningiomas (diameter >5 cm) extending to the middle fossa in four different neurosurgical centers within 6 years. Depending on the localization of the tumor, the skin incision was between 2.5 and 3 cm long and was made without shaving the patient's eyebrow hair. Subsequently, a keyhole craniotomy was performed of approximately 0.8×1.2-1.4 cm in diameter. Preoperative and postoperative clinical and radiological data were analyzed and discussed. RESULTS: Headache and psycho-organic syndrome were the most common presenting symptom in all patients. Presenting symptoms were associated with psychological changes in 23 cases, visual impairment in 19 patients, and anosmia in 17 patients. In overall, 36 of 40 patients (90%) showed a good outcome and returned at long-term follow-up to their previous occupations. The elderly patients returned to their daily routine. CONCLUSION: With the appropriate keyhole approach as a refinement of the classic keyhole craniotomy to a smaller key"burr"hole, and with use of modern and new designed equipment, it is possible to perform complete resection of large anterior and middle fossa meningiomas with the same safety, efficiency and with less complication rates as described in the literature for large meningiomas even performed with classic keyhole craniotomies.

Imaging of gliomas with Cis-4-[18F]fluoro-L-proline.

Tumor imaging with cis-4-[18F]fluoro-L-proline (cis-FPro) was compared to that of L-[3H]proline and L-[3H]methionine in F98 rat gliomas by dual-tracer autoradiography. All tracers exhibited high accumulation in the tumors but in the normal brain significant uptake was observed for L-[3H]methionine only. Tumor extent on autoradiograms with L-[3H]proline and L-[3H]methionine was identical to that of histological staining while autoradiograms of cis-FPro showed diffuse uptake in the penumbra of some tumors. First PET studies in 7 patients with cerebral gliomas demonstrated accumulation of cis-FPro in tumor areas with enhancement of Gd-DTPA on MR scans. Uptake of cis-FPro in normal brain tissue was negligible. In one patient with a glioblastoma accumulation of cis-FPro was also found in two brain areas without enhancement of Gd-DTPA on MR scans. Control of MRI suggested tumor growth in these areas at further follow up. Our results indicate that in most gliomas increased cis-FPro uptake is restricted to areas with disruption of the BBB which limits its clinical utility.

[Circadian rule and activity periodicity in the genus carabus]. / Circadian-Regel und Laufaktivität der Caraben (Ins. Coleoptera).

In the strictly dark-active C. problematicus and the mainly dark-active C. cancellatus the Aschoff-rule is effective only between 0 and 2 (4) Lux. The circadian rule is violated by these species because no correlation exists between the quotient α/ϱ and the period length τ. Spontaneous changes of α/ϱ are not associated with changes of τ in the sense of the circadian rule. τ and light intensity are correlated with certain regularity, but no correlation could be found between light intensity and quantity of activity.

Endoscopic endonasal transsphenoidal approach for resection of a coexistent pituitary macroadenoma and a tuberculum sellae meningioma.

The coexistence of a pituitary macroadenoma and a tuberculum sellae meningioma is very rare. This article demonstrates the surgical technique of the simultaneous resection of a pituitary macroadenoma and a tuberculum sellae meningioma using an endoscopic, endonasal, biportal, transsphenoidal approach. A 36-year-old woman presented with frontal headache and extended visual field loss of the right eye. She underwent cranial magnetic resonance imaging (MRI) revealing a 2 × 2 × 2.5 mm contrast-enhancing intrasellar and suprasellar lesion with compression of the optic chiasma. The coexistence of a pituitary macroadenoma and meningioma was suggested. A biportal endoscopic endonasal transsphenoidal approach was performed to remove both lesions. The histological results confirmed the coexistence of the pituitary macroadenoma and meningioma, World Health Organization (WHO) grade I. The endoscopic, endonasal, transsphenoidal approach is a safe and reliable minimal invasive surgical alternative for resection of the intra-, supra- and parasellar lesions, avoiding additional craniotomy.

Laparoscopy for a ventriculoperitoneal shunt tube dislocated into the colon.

INTRODUCTION: Implantation of a ventriculoperitoneal (VP) shunt is a standard procedure for hydrocephalus. Different complications can occur, one of them being migration of the distal end of the tube. CASE DESCRIPTION: The abdominal end of a VP shunt tube had migrated into the descending colon. In a laparoscopic procedure, the shunt was retrieved, and the colonic perforation site was resected. The patient had a favorable outcome. DISCUSSION: Laparoscopy can play a key role and is recommended not only to make an exact diagnosis, but also for definite, safe, and trauma-minimizing treatment of intraabdominal VP shunt dysfunction.

Predictors of subsequent overdrainage and clinical outcomes after ventriculoperitoneal shunting for idiopathic normal pressure hydrocephalus.

BACKGROUND: Little is known about variables associated with overdrainage complications and neurofunctional and health-related quality of life outcomes in idiopathic normal-pressure hydrocephalus (iNPH) patients after shunt surgery. OBJECTIVE: To identify candidate demographic and disease-specific predictors of overdrainage and patient-related outcomes, allowing for more personalized care of patients with iNPH. METHODS: This was a secondary analysis of the dataset of the SVASONA study, a multicenter randomized trial comparing gravitational and conventional gravitational valves for treating iNPH. We evaluated the association between baseline items and the incidence of overdrainage, using different endpoint definitions. RESULTS: We identified only a few variables associated with a possible increased risk of overdrainage. Apart from using conventional rather than gravitational valves, longer duration of surgery and female sex were associated with a higher risk of clinical signs and symptoms suggestive of overdrainage (hazard ratio: 1.02, 95% confidence interval: 1.01-1.04 and 1.84, 95% confidence interval: 0.81-4.16). The occurrence of clinical symptoms of overdrainage, and the need for exchanging a programmable by a gravitational valve may adversely affect disease-specific outcomes like the Kiefer score. CONCLUSION: Few, if any, baseline and treatment characteristics may be helpful in estimating the individual risk of complications and clinical outcomes after shunt surgery for iNPH. Patients should be informed that longer surgery for any reason may increase the risk of later overdrainage. Also, women should be counseled about a sex-associated increased risk of the development of clinical symptoms of overdrainage, although the latter cannot be distinguished from a generally higher prevalence of headaches in the female population.

[Cervical arthroplasty using the Bryan Cervical Disc System]. / Arthroplastie an der Halswirbelsäule mit der Bryan-Prothese.

OBJECTIVE: Treatment of radicular or myelopathic symptoms of the vertebral segments from C2 through Th1. INDICATIONS: Discogenic and/or spondylotic radiculopathy. Acute myelopathy. Acute or progressive functional neurological deficit. Persistent pain resistant toward conservative treatment for > 6 weeks. CONTRAINDICATIONS: Chronic myelopathy. Spondylotic myelopathy. Infection. Tumor in the vertebral segment. Ossification of the posterior longitudinal ligament (OPLL). Metabolic bone disease. Osteoporosis. Long-lasting steroid medication. Allergy to titanium, polyurethane and ethylene oxide. Bekhterev's disease. Bony segmental fusion. Instability. SURGICAL TECHNIQUE: Using the Bryan Cervical Disc Template Set together with magnetic resonance or computer tomographic images, the exact size of the prosthesis will be selected. The patient is lying in a supine position and the level of surgery is verified fluoroscopically. Diskectomy and decompression are performed via an anterior approach. After preparation of the implant bed, the center of the disk space is established using a transverse centering tool and inserting the Bryan cervical distractor. Before the prosthesis can be inserted, the end plates have to be milled. The prosthesis is filled with sterile saline solution and inserted. Proper fitting is verified fluoroscopically. POSTOPERATIVE MANAGEMENT: Depending on the clinical situation postoperatively, the patient is discharged. Wound clamps are distracted on day 8, support by a cervical collar is not necessary. Light physical manipulations for muscle relaxation can be performed. RESULTS: Since 2002, 178 patients have received at least one Bryan Cervical Disc Prosthesis. 92 patients had a complete follow- up. Examinations were performed 8 and 12 weeks, respectively, as well as 6 up to 44 months postoperatively. 29 patients received a hybrid implantation. Cobb's angle and range of motion were determined radiologically, the degree of heterotopic ossification was classified according to McAfee. Disk prosthesis placement was measured in relation to the dorsal edge of the vertebral body, the center of the spine, as well as the body axes. For clinical evaluation, the Oswestry Neck Disability Index was used, and the neurostatus was determined.

The adjustable proGAV shunt: a prospective safety and reliability multicenter study.

OBJECTIVE: To evaluate the reliability of the gravitation-assisted adjustable proGAV shunt system with a prospective multicenter study conducted in 10 German hospitals. METHODS: Enrollment for this observational study began in April 2005 and concluded in February 2006. The protocol required re-examinations 3 and 6 months postoperatively and fixed the endpoint of follow-up at 12 months after implantation. Patients with different types of adult, juvenile, and pediatric hydrocephalus were included and 165 patients were enrolled; 9 died and 12 had incomplete follow-up. RESULTS: Of the assessable 144 patients, 130 completed the protocol after 12 months, whereas 14 failed because of the need to explant the device, mainly because of infection. In 12 patients, components of the shunt, not the valve, were revised. In 65 of the 144 patients, there were 102 readjustments of the valve in 67 incidences because of underdrainage and in 35 because of overdrainage. In 1 case, readjustment was not possible. Determination of pressure level with the verification instrument was safe and corresponded to the required x-ray controls after adjustments. No unintended readjustments were noted. CONCLUSION: The proGAV is a safe and reliable device.

Safety, tolerability, and tumor response of IL4-Pseudomonas exotoxin (NBI-3001) in patients with recurrent malignant glioma.

PURPOSE: This was an open-label, dose-escalation trial of intratumoral administration of IL-4 Pseudomonas exotoxin (NBI-3001) in patients with recurrent malignant glioma. PATIENTS AND METHODS: A total of 31 patients with histologically verified supratentorial grades 3 and 4 astrocytoma were studied. Of these, 25 patients were diagnosed with glioblastoma multiforme (GBM) while six were diagnosed with anaplastic astrocytoma. Patients were over 18 years of age and had Karnofsky performance scores > or = 60. Patients were assigned to one of four dose groups in a dose-escalation fashion: 6 microg/ml x 40 ml, 9 microg/ml x 40 ml, 15 microg/ml x 40 ml, or 9 microg/ml x 100 ml of NBI-3001 administered via convection-enhanced delivery intratumorally using stereotactically placed catheters. Patients were followed with serial MRI scans and clinical assessments every four weeks for the first 16 weeks and then every eight weeks until week 26. RESULTS: No drug-related systemic toxicity, as evident by lack of hematological or serum chemical changes, was apparent in any patients; treatment-related adverse effects were limited to the central nervous system. No deaths were attributable to treatment. Drug-related grade 3 or 4 toxicity was seen in 39% of patients in all dose groups and 22% of patients at the maximum tolerated dose of 6 microg/ml x 40 ml. The overall median survival was 8.2 months with a median survival of 5.8 months for the GBM patients. Six-month survival was 52% and 48%, respectively. Gadolinium-enhanced magnetic resonance imaging of the brain showed areas of decreased signal intensity within the tumor consistent with tumor necrosis following treatment in many patients. CONCLUSIONS: NBI-3001 appears to have an acceptable safety and toxicity profile when administered intratumorally in patients with recurrent malignant glioma.