M. Löhr

Relevance of ICP and ptiO2 for indication and timing of decompressive craniectomy in patients with malignant brain edema

SummaryBackground. The exact effects of decompressive craniectomy on intracranial pressure (ICP) and cerebral tissue oxygenation (ptiO2) are still unclear. Therefore, we have monitored ICP and ptiO2 intra-operatively and correlated these values to different operative steps during craniectomy.Methods. ICP and ptiO2 values have been monitored both, simultaneously and continuously, in 15 patients with cerebral edema due to posttraumatic or postischemic brain swelling. Indications for craniectomy were an increase in ICP above 25u2009mmHg or a decrease in ptiO2 below 10u2009mmHg resistant to conservative treatment (e.g. mannitol, hyperventilation, adequate arterial blood oxygenation, etc.). In all cases, we performed a fronto-temporo-parietal craniectomy (15×12u2009cm) and dura enlargement with galea-periosteum. During craniectomy, monitoring of ICP and ptiO2 in the affected hemisphere was continued. Values were recorded and correlated with the different operative steps.Findings. We performed craniectomy according to our treatment protocol in 5 patients. Prior to surgery, mean ICP values were 25.6u2009mmHg (range: 23–29u2009mmHg), mean ptiO2 values were 5.9u2009mmHg (range: 2.4–9.5u2009mmHg), and mean CPP values were 66u2009mmHg (range: 60–70u2009mmHg). After removing the bone flap, ICP values dropped to physiological values (mean: 7.4u2009mmHg), whereas ptiO2 values increased only slightly (mean: 11u2009mmHg). Opening of the dura resulted in a further decrease of ICP (mean 4.8u2009mmHg) and an increase of ptiO2 to normal limits (mean: 18.8u2009mmHg). After skin closure, mean ICP was 6.8u2009mmHg and mean ptiO2 was 21.7u2009mmHg, respectively. We found a significant decrease of ICP after craniectomy (p<0.042) and after dura enlargement (p<0.039) as well as a statistically significant increase in ptiO2 after craniectomy (p<0.043) and after dura enlargement (p<0.041).Conclusion. As a large bone flap in decompressive craniectomy is essential for adequate ICP reduction, the results of the presented cases suggest that dura enlargement is the crucial step to restore adequate brain tissue oxygenation and that ptiO2 monitoring could be an important tool for timing craniectomy in the future.

Spinal epidural abscess: prognostic factors and comparison of different surgical treatment strategies.

SummaryBackground. Spinal epidural abscess (SEA) is a rare but potentially devastating disease requiring immediate surgical intervention and appropriate antibiotic treatment. The standard approach to decompress SEA is laminectomy. No report covers comprehensively the indications for the less invasive interlaminar approach, the usefulness of intra-operative ultrasonography and the suspected benefit of inserting a suction-irrigation drainage.Method. A retrospective evaluation of the medical and radiological data was undertaken in 27 consecutive patients with SEA operated on during a period of 10 years by a dorsal approach. Factors influencing outcome were evaluated with special regard to different surgical strategies concerning the invasiveness of the operative approach, the use of intra-operative ultrasound and the use of different drainage systems.Findings. Outcome was mainly determined by the pre-operative neurological condition and the localization of the abscess. Recurrence rate was dependent on the longitudinal extent of the mass and the intra-operative finding of granulation tissue, but not on the administration of a postoperative suction-irrigation drainage. An interlaminar approach was equally matched to a decompression by laminectomy in lumbar SEA concerning the incidence of residual/recurrent abscess formation. In concomitant spondylodiscitis, laminectomy bore the risk of the formation of a postoperative kyphotic deformity. The use of intra-operative ultrasound allowed the visualization of hidden inflammatory masses and, thus, reduced the rate of residual abscess formation.Conclusion. An interlaminar approach should be considered instead of laminectomy in lumbar SEA and in impending anterior column instability due to spondylitis. Intra-operative ultrasound is a beneficial aid for the determination of the extent of decompression during surgery and is practicable even through a narrow interlaminar bony window. The insertion of postoperative suction-irrigation drainage had no beneficial effect on outcome but bore the risk of epidural fluid congestion.

CT-guided percutaneous aspiration of Tarlov cyst as a useful diagnostic procedure prior to operative intervention

SummaryTarlov or perineural cysts are lesions of the nerve root most often found in the sacral region. Several authors recommend surgical treatment of symptomatic Tarlov cysts. However, successful surgical treatment is dependent on appropriate patient selection.In this article, we report three cases of a sacral perineural cyst, causing sciatic pain, and emphasize the usefulness of CT-guided percutaneous aspiration as an important diagnostic and prognostic procedure prior to definitive operative treatment.

Delayed bilateral craniectomy for treatment of traumatic brain swelling in children: case report and review of the literature.

IntroductionHead injury is the leading cause of accidental death in children. Recent reports have shown the benefit of decompressive craniectomy in children and the role of early timing has been emphasized. However, there is still a lack of data to determine the optimal time for performing craniectomy.Case report In contrast to most reports in the literature, this case report demonstrates successful bilateral decompressive craniectomy in a 10-year-old girl with multiple posttraumatic intracranial lesions and massive traumatic brain swelling on the 8th posttraumatic day.Conclusions Various pathophysiological mechanisms in the genesis of posttraumatic brain swelling make different treatment strategies necessary. Continuous monitoring of intracranial pressure (ICP), as well as serial cranial computed tomography (CCT), can help to differentiate between these mechanisms. Furthermore, repeated clinical and neurophysiological investigations are important for the timing of craniectomy.

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy.

SummaryInterbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if “hard disc prolaps” is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications.Thirteen patients – 5 men and 8 women with an average age of 49 years – with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen.The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.

Degeneration of cholinergic rat basal forebrain neurons after experimental subarachnoid hemorrhage.

OBJECTIVEThe reasons for neuropsychological deficits after subarachnoid hemorrhage (SAH) are fairly unknown. Cholinergic basal forebrain (BFB) neurons are essential for attention, memory, and emotion. We investigated possible changes in the cholinergic BFB and its hippocampal and neocortical terminals after experimental SAH. METHODSSAH was induced in 19 male Wistar rats by stereotactic injection of 150 μL of autologous blood into the prechiasmatic cistern. Five control animals received 150 μL of saline. Continuous monitoring of brain tissue oxygen tension, intracranial pressure, and cerebral perfusion pressure was performed. After 4 and 14 days, the BFB was analyzed for cholinergic and γ-aminobutyric acid-ergic cell counts. The number of cholinergic terminals in the hippocampus and neocortex was calculated by optical densitometry. RESULTSSAH resulted in a 20 to 30% decrease in cholinergic BFB neurons in the medial septum and diagonal band at 4 and 14 days. A similar decline in the density of hippocampal and neocortical cholinergic terminals was demonstrated. Animals treated with saline did not exhibit significant cholinergic cell loss, and γ-aminobutyric acid-ergic neurons appeared unaffected by the SAH. Courses of intracranial pressure and cerebral perfusion pressure did not differ between animals injected with blood and saline, but brain tissue oxygen tension decreased considerably and continued to stay below baseline in SAH, although it returned to normal values after saline injection. CONCLUSIONThe present study provides evidence for a decrease of cholinergic BFB neurons after SAH. The direct effect of blood in the basal cisterns seemed to result in an enduring tissue hypoxia as a significant mechanism for cholinergic degeneration.

Transmigration of fibrino-purulent inflammation and malignant cells into an artificial dura substitute (Neuro-Patch®): report of two cases

PurposeThe objective of this work was to present possible, though rare, complications of Neuro-Patch® implantation after brain surgery.MethodsTwo patients, aged 62 and 63xa0years, who had a partial dural substitution with an artificial polyurethane graft after neurosurgical resection of a gross tumour, are presented.ResultsIn the two patients, the avital tissue was infiltrated by either inflammatory or neoplastic tissue respectively.ConclusionsThis report demonstrates a new pathological point of view in using synthetic materials for the reconstruction of dural defects.

Treatment strategies of space-occupying intradural metastases of the cauda equina of nonneurogenic origin

BackgroundCompressive intradural metastases of the cauda equina are a rare site of metastatic spread in systemic cancer. So far, only few reports have been published with conflicting statements concerning a surgical versus nonsurgical approach.MethodFive patients with symptomatic space-occupying intradural metastases of the cauda equina were analyzed retrospectively, focusing on the influence of surgical intervention on pain relief, neurological outcome and thus the patients’ quality of life.FindingsAt the time of diagnosis, all patients were in an advanced metastatic state. Surgical resection was the primary treatment in four patients and radiotherapy in one. Despite infiltration of the cauda rootlets, gross total tumour resection could be achieved in two of the four patients treated surgically. Functional outcome was beneficial in these patients with marked and immediate relief of pain and improvement of motor function even following incomplete tumour resection.ConclusionsSurgical treatment of compressive intradural metastases of the cauda equina seems to be feasible with low operative risk and with the potential benefit of an immediate relief of pain and improvement in motor function and thus an increase in quality of life.