Mononostril endoscopic transsphenoidal approach to sellar and peri-sellar lesions: Personal experience and literature review.

OBJECTIVE: The endonasal endoscopic approach to skull base is still under investigation. The main goal is the minimal invasive approach to pathologies with a better rate of resection without retraction of the brain tissue. Here, the authors report their technique of transnasal endoscopic neurosurgery using a mononostril approach and its development. METHODS: The supplementary video demonstrates the different steps of the mononostril approach and resection of a pituitary adenoma. All video-recorded procedures that were carried out between 2000 and 2013 using this technique were analysed. The patients were followed prospectively. RESULTS: Visualization and handling were good in 246/251 (98%). In three cases, we had to switch to microscopy because of severe bleeding of the cavernous sinus. On follow-up, magnetic resonance imaging revealed radical tumour resection in 92% of all cases when intended. There was no mortality, and the low complication rate was remarkable. CONCLUSION: Our mononostril approach of transnasal transsphenoidal surgery shows better results compared with previously published reports in regards to radicality, low cerebrospinal fluid leaks and morbidity. The very low rate of nasal complains is particularly remarkable.

Endoscopic diagnosis and treatment of far distal obstructive hydrocephalus.

PURPOSE: Obstruction of the CSF circulation distal to the fourth ventricle is a rare cause of noncommunicating hydrocephalus. Endoscopic third ventriculostomy (ETV) represents one of the treatment options, but reports of results are rare. METHODS: Between March 1997 and June 2008, 20 ETVs in 20 patients (mean 32.4 years, range 1 month-79 years) for noncommunicating hydrocephalus distal to the fourth ventricle were undertaken. All patients suffered from severe internal hydrocephalus and typical clinical symptoms. In addition to the standard ETV, a transaqueductal inspection of the posterior fossa with a flexible scope was performed. All patients were prospectively followed. RESULTS: An ETV was achieved in all patients. It was clinically successful in 15 of 20 patients (75%) with an improvement of 50% (three out of six) of the pediatric and of 83% (12 out of 14) of the adult population. A reduction of ventricle size was found in ten (50%). Five patients (25%) received ventriculoperitoneal shunting. A transaqueductal inspection of the posterior fossa cerebrospinal fluid (CSF) pathways was performed in 16. In the remaining four patients, no inspection with the flexible scope was done. One clinically silent fornix contusion and one CSF fistula which was treated conservatively occurred. There was no permanent morbidity. CONCLUSIONS: ETV is a successful treatment option in CSF pathway obstructions distal to the fourth ventricle. Although the success rate particularly of the pediatric population appears to be lower than with other indications of obstructive hydrocephalus, a relevant part of the patient population improves after ventriculostomy and shunting can be avoided.

Endoscopic third ventriculostomy in obstructive hydrocephalus due to giant basilar artery aneurysm.

OBSTRUCTIVE: hydrocephalus due to giant basilar artery (BA) aneurysm is a rare finding, and endoscopic treatment has not been reported. Here the authors present their experience with endoscopic third ventriculostomy (ETV) in obstructive hydrocephalus due to giant BA aneurysm. Between December 2000 and March 2007, 3 patients (2 men and 1 woman; age range 32-80 years) underwent an ETV for the treatment of obstructive hydrocephalus caused by a giant BA aneurysm. All 3 patients presented with cephalgia, nausea, vomiting, and a variable decrease in consciousness. An obstructive hydrocephalus caused by a giant BA aneurysm was found in each case as the underlying pathological entity. Intraoperatively, a narrowing of the third ventricle by upward displacement of the tegmentum was found in all 3 patients. A standard ETV was performed and included an inspection of the prepontine cisterns. The endoscopic treatment was successful in all patients with respect to clinical signs and radiological ventricular enlargement. No complications were observed. In all, the endoscopic ventriculostomy was proven to be a successful treatment option in obstructive hydrocephalus even if it is caused by untreated giant BA aneurysm.

Endoscopic cystoventriculostomy for treatment of paraxial arachnoid cysts.

OBJECT: The optimal therapy of arachnoid cysts is controversial. In symptomatic extraventricular arachnoid cysts, fenestration into the basal cisterns is the gold standard. If this is not feasible, shunt placement is frequently performed although another endoscopic option is available. METHODS: Between March 1997 and June 2006, 12 endoscopic cystoventriculostomies were performed for the treatment of arachnoid cysts in 11 patients (4 male and 7 female patients, mean age 52 years [range 14-71 years]). All patients were prospectively followed up. RESULTS: In 11 cases, the arachnoid cysts were frontotemporoparietal and fenestration was performed into the lateral ventricle. In 1 case, the arachnoid cyst was located in the cerebellum and the cyst was fenestrated into the fourth ventricle. Neuronavigational guidance was used in all but 1 case. Endoscopic cystoventriculostomy was performed in all cases without complications. No stents were placed. The mean surgical time was 71 minutes (range 30-110 minutes). The mean follow-up period was 42.7 months (range 19-96 months) per surgical case and 48.8 months (range 19-127 months) per patient. Symptoms improved after 11 of the 12 procedures; 7 of the 11 patients became symptom-free and the others had only mild residual symptoms. The patient who did not experience clinical improvement suffered from depression and demonstrated a significant decrease of the cyst size on the postoperative MR imaging. After 11 of 12 procedures, a decrease in cyst size was observed. In 1 case, a subdural hematoma developed; it required surgical treatment 3 months after surgery. In another case, reclosure of the stoma required repeated endoscopic cystoventriculostomy more than 7 years after the initial procedure. CONCLUSIONS: Overall, endoscopic cystoventriculostomy represents a useful treatment option for patients with paraxial arachnoid cysts in whom a standard cystocisternotomy is not feasible. Based on the results in this case series, stent placement appears not to be required. Despite the long mean follow-up of almost 4 years, however, a longer follow-up period seems to be required before definite conclusions can be drawn.

German neuroendoscopy above the skull base.

Endoscopy plays an important part in current minimally invasive neurosurgery. The concepts, indications, and standards of current neuroendoscopy were developed in the beginning of the 1990s by several groups of neurosurgeons. Several factors contributed to its success and acceptance, including technical development, influence of other disciplines, and adaptation to neurosurgical requirements. This historical survey focuses on the period when this technique initially emerged, including the scientific discussions of each group as well as the arguments and reasons that led to present intraventricular neuroendoscopy. Interestingly, despite the almost independent development of neuroendoscopic systems and techniques, the available systems and techniques applied these days grossly correspond. Rigid rod-lens endoscopes are generally accepted as the best option among the various available instrument sets. Nevertheless, frameless as well as frame-based stereotactic endoscopy and flexible steerable endoscopes might have their applications as well.

A new endoscopic spine system: the first results with "Easy GO".

PURPOSE: Endoscopy meets increasing interest by spine surgeons. However, endoscopic results are diverging and many spinal endoscopic systems are difficult to apply and handle. METHODS: A system for endoscopic spinal surgery was developed where the main goals were: (1) easy intraoperative handling with standard microsurgical techniques, and (2) avoidance of a prolonged learning curve. The system consists of various dilators, two different work sheaths, two different 30 degrees endoscopes, and an endoscope holder. RESULTS: Between August 2006 and April 2008, 80 spinal surgeries were performed in degenerative lumbar spine cases (mean age 52 years, range 22-85 years). Intraoperatively, the system was easy to handle. Standard microsurgical techniques were used. Mean surgical time scored 75 min (range 28-168 min). There was no intraoperative complication, no new postoperative deficit and no infection. In four cases, the endoscope was abandoned and the procedure microsurgically continued (5%). At the last follow-up (mean FU 10 months, range 2 weeks up to 21 months), 89% of the patient were pain free (71/80). Four patients suffered from recurrent disc prolapses (5%). Another five patients (6%) were not satisfied without evidence of re-prolaps. Of those who answered the questionnaire of patient satisfaction, 83% (45/54) considered their postoperative status as excellent, 13% as good (7/54), 4% were not satisfied (2/54). CONCLUSIONS: The Easy GO system was easy and safe to handle with the standard bimanual microsurgical technique and good postoperative results. Further studies are needed to show a significant advantage of the technique in comparison to the microsurgical standard procedure.

PEEK cage cervical ventral fusion in spondylodiscitis.

PURPOSE: Cervical spondylodiscitis is a quite rare finding regarding the number and the common location of spinal abscesses in the lumbar region. While in thoracic and lumbar discitis, single-step surgery with neural decompression, disc space evacuation, and subsequent fusion is well known, there is no such report in cervical discitis. Here the authors present their experience with ventral polyetherketone (PEEK) cage fusion in cervical spondylodiscitis in a single-step procedure. METHODS: Between January 2006 and November 2008, five patients (three men, two woman; ages 71, 77, 58, 66 and 66 years) suffering from cervical spondylodiscitis and epidural abscess underwent disc evacuation, myelon decompression and subsequent ventral fusion using an empty PEEK cage disc replacement in one single setting. All five patients presented with significant neurological symptoms like cervicobrachialgia, tetraparesis and disturbance of the urinary incontinence. In all five patients, disc evacuation, myelon decompression and cervical fusion using a PEEK cage disc replacement in a single-stage surgery were performed. All wounds were closed primarily. Postoperatively, all patients received a specific antibiotic therapy for at least 6 weeks. RESULTS: This treatment strategy was successful in all patients with respect to clinical signs, laboratory parameters and radiological findings. All patients improved neurologically. Follow-up revealed a stable osteosynthesis without signs of instability. One cage was explanted despite neurological improvement and normal infectious parameters at another surgical department. No complications were observed. CONCLUSIONS: In all, abscess drainage and ventral fusion with PEEK-cage disc replacement in one single setting was proven to be a successful treatment option in cervical discitis and spinal epidural abscess.

Comparison of the long-term results of anterior transposition of the ulnar nerve or simple decompression in the treatment of cubital tunnel syndrome--a prospective study.

OBJECTIVE: In order to assess their late benefits we present the long-term results of a comparison of treating cubital tunnel syndrome with anterior submuscular transposition or simple decompression. METHODS: Of 40 patients initially recruited to this study 33 were available for long term follow-up. Sixteen patients underwent anterior submuscular transposition (group A); simple decompression was performed in 17 of the patients (group B). The indications for inclusion were a typical clinical presentation confirmed by abnormal nerve conduction studies. The mean duration of the symptoms before operation was 13 months (range 2 to 84 months) in group A and 8.4 months (range 1.5 to 36 months) in group B. All patients were seen 2 months after surgery and at least 3 years later. The mean duration of follow-up was 63.1 month in the first group and 52 months in the second group. RESULTS: No complications were seen in either group. In the group treated by anterior transposition, ten of 16 patients were completely free of signs and symptoms; slight residual hypesthesia or paresthesia was observed in two patients. Paresis and atrophy was observed in only one person. In the simple decompression group, 11 of 17 patients were completely free of signs and symptoms. In five patients slight residual symptoms were observed; no paresis or atrophy was reported in any of this group. CONCLUSION: These long-term results show that both surgical techniques have a good outcome. Thus, the less invasive simple decompression should be preferred.

Chronic subdural hematoma--craniotomy versus burr hole trepanation.

The authors present a series of more than 200 surgical procedures for chronic subdural hematoma in a 5-year-period. Clinical presentation and neurosurgical treatment were regarded with a special focus on the surgical technique. Between March 2003 and July 2008, 193 patients (113 male and 80 female, mean age 72.5 yrs [range 26-97 yrs]) suffering from chronic subdural hematoma were retrospectively analyzed. One-hundred-fifty-one craniotomies and 42 burr holes were performed. Forty-two craniotomy patients (27.8%) in contrast to 6 burr hole patients (14.3%) required surgical revision. A craniectomy was performed as an ultima ratio after at least 2 prior evacuations in 3 cases. Chronic subdural hematoma is a disease of the elderly. A craniotomy seems to possess a higher rate of recurrence of the chronic subdural hematoma so that a burr hole evacuation should be preferred. Craniectomy might be a good therapeutic option in complicated recurrent chronic subdural hematomas.

Long-Term Reliability of Neuroendoscopic Aqueductoplasty in Idiopathic Aqueductal Stenosis-Related Hydrocephalus.

BACKGROUND: During the 1990s, endoscopic aqueductoplasty (AP) was considered to be a valuable alternative to endoscopic third ventriculostomy (ETV) in treating hydrocephalus related to idiopathic aqueductal stenosis (iAS), with promising short-term outcomes. OBJECTIVE: To evaluate the long-term outcome of AP in the treatment of iAS. METHODS: Long-term follow-up clinical examinations and magnetic resonance (MR) imaging were performed for patients treated by an AP for iAS in our department. RESULTS: Twenty patients (14 female, 6 male, mean age 41.7 yr, range 0.5-67 yr) were treated between 1996 and 2002. Two patients were lost to long-term follow-up. One patient died 6 mo after AP, but death was not related to the procedure. The mean follow-up for the remaining 17 patients was 120 mo. Clinically relevant aqueductal reclosure was observed in 11/17 patients after a mean follow-up of 53.4 mo. These 11 patients underwent ETV, which has been successful during further follow-up. Four of the six remaining patients presented with no clinical symptoms, although aqueductal restenosis was observed on MR imaging. Thus, the overall failure rate of AP was 88.2%. The failures were homogeneously distributed over the entire follow-up period. CONCLUSION: AP has a high risk of failure during long-term follow-up and is not recommended as the first choice of treatment in hydrocephalus caused by iAS. ETV should be done instead. AP may be reserved for a limited number of patients in whom ETV is not feasible but should be combined with stenting to avoid reclosure of the aqueduct.

Long-Term Results After Endoscopic Resection of Colloid Cysts.

BACKGROUND: Endoscopic resection of colloid cysts is a widely accepted treatment option instead of microsurgery. However, there is still a debate about a potentially higher rate of incomplete resections and recurrence. OBJECTIVE: The aim of this retrospective study was to evaluate long-term results after endoscopic removal of colloid cysts. METHODS: Twenty patients underwent endoscopic treatment in our department. Eighteen patients agreed to follow-up examinations. In 17 patients, magnetic resonance images were obtained. RESULTS: Total cyst resection was achieved in 16 procedures. In 1 patient, only plexus coagulation and widening of the ipsilateral foramen of Monro were performed. In 3 patients, small remnants of the cyst membrane were left behind. Conversion to microsurgery became necessary in 1 patient. Mild temporary complications occurred in 6 patients. Preoperative symptoms were completely relieved in 16 patients and improved in 2 patients. The average follow-up period was 188 months. In the patient with plexus coagulation, the cyst did not change. Recurrence occurred in 2 of 3 patients with cyst remnants. To date, no cyst remnant or recurrence has caused any symptoms or required surgical treatment. CONCLUSIONS: Our results indicate that endoscopic treatment of colloid cysts is a safe and effective treatment option that provides excellent long-term results. However, we determined that a significant risk for recurrence exists when even small parts of the cyst capsule were left behind. Therefore, we advocate an attempt at total endoscopic cyst resection.

Endoscopic Third Ventriculostomy before Posterior Fossa Tumor Surgery in Adult Patients.

OBJECTIVE: Obstructive hydrocephalus in patients with posterior fossa tumors is frequently seen. Treatment options include immediate tumor removal or prior cerebrospinal fluid (CSF) diversion procedures. The necessity and feasibility of an ETV in these situations has not yet been proven in adult patients. METHODS: We retrospectively reviewed our prospectively maintained database for ETVs before surgery of posterior fossa tumors in adults. The primary focus of data analyses was the question of whether the ETV was suitable to treat the acute situation of hydrocephalus without an increased rate of complications due to the special anatomical situation with a posterior fossa tumor. We also analyzed whether any further CSF diverting procedures were necessary. RESULTS: A total of 40 adult patients who underwent an ETV before posterior fossa tumor surgery were analyzed. Overall, 33 patients (82.5%) had clinical signs of hydrocephalus, and all of them improved in their clinical course after ETV. Seven patients (17.5%) did not demonstrate clinical signs of hydrocephalus, but ETV was performed with prophylactic or palliative intent in six patients and one patient, respectively. No complications were observed due to ETV itself. No permanent shunting procedure was necessary in a mean follow-up of 76.5 months. Early additional CSF diverting procedures (redo ETV, external ventricular drain) were performed in five patients (12.5%). CONCLUSION: The present series confirms the feasibility and safety of ETV before posterior fossa tumor surgery in adult patients. If patients had symptomatic hydrocephalus before tumor surgery, an ETV can be performed, followed by early elective tumor surgery. A prophylactic ETV in asymptomatic patients is not advised. Early elective tumor surgery should be performed in these patients.

The use of waterjet dissection in endoscopic neurosurgery. Technical note.

Waterjet dissection enables vessel preservation and a reduction in intraoperative blood loss. Because even minimal bleeding should be avoided during neuroendoscopy, the waterjet device may be a particularly valuable tool in such procedures. The authors used this instrument in experimental endoscopic procedures in 20 cadaveric porcine brains and clinically in four patients with obstructive hydrocephalus. A precise and accurate septostomy was achieved in all of the pig brains. In two patients the hydrocephalus was due to intraventricular hemorrhage, in one a posterior fossa tumor, and in one a cystic craniopharyngioma. In all patients the surgical view was kept clear with waterjet irrigation and suction. Using a pressure setting of 10 bars, the waterjet device successfully perforated the cyst wall of the craniopharyngioma in one patient and the floor of the third ventricle in three patients. The use of the waterjet device in selected endoscopic procedures appears safe, and may help reduce intraoperative bleeding. However, further studies are needed to confirm the utility of the waterjet tool in endoscopy.

The endoscopic endonasal transsphenoidal approach to sellar lesions allows a high radicality: The benefit of angled optics.

OBJECTIVE: The endonasal endoscopic approach is currently under investigation for perisellar tumour surgery. A higher resection rate is to be expected, and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery with a special reference to the impact of the use of angled optics. MATERIAL AND METHODS: Two-hundred-and-seventy-one endoscopic endonasal transsphenoidal procedures were performed for sellar lesions between January 2000 and August 2013. One-hundred-and-twenty-nine patients out of them could be used for analysing the use of angled endoscopes including completed follow up, MR imaging as resection control and documentation of the intraoperative use and benefit of angled optics. Exclusion criteria were: planned incomplete resection or incomplete data set. The surgical technique was carefully analysed; and these cases were followed prospectively. RESULTS: Standard technique was a mononostril approach with 0° endoscopes. Angled endoscopes were used for assessment of radicality during the tumour resection and at the end of the procedure. In 95 cases (72%), an angled endoscope was used. Remnant tumour was visualized with angled optics in 27 of the 95 cases (28%). In all these cases, remnant tumour tissue was subsequently further removed. Complete resection was seen on MRI FU in 91 of 95 cases (96%) in this subgroup. In the cases without application of angled optics, there was already a sufficient sight via the 0° endoscope (14/34; 42%), or a significant bleeding from the cavernous sinus made the application of an angled endoscope impossible (19/34; 55%). On follow up, MRI revealed radical tumour resection in 93% (120/129). In the subgroup without angled optics use, radicality reached 88% (30/34) in contrast to 96% in the angled optics subgroup. Recurrent tumour growth was observed in four patients (3%). CONCLUSIONS: The endscopic technique has been shown to be safe and successful with a high radicality and only minor complications. The application of various angled endoscopes allows a look "around the corner" resulting in a potentially higher radicality of tumour resection in endonasal transsphenoidal surgery.

Endoscopic Biopsy for Intra- and Paraventricular Tumors: Rates of Complications, Mortality, and Tumor Cell Dissemination.

BACKGROUND AND STUDY AIM: Intra- and paraventricular tumors are frequently associated with cerebrospinal fluid (CSF) pathway obstruction. Thus the aim of an endoscopic approach is to restore patency of the CSF pathways and to obtain a tumor biopsy. Because endoscopic tumor biopsy may increase tumor cell dissemination, this study sought to evaluate this risk. PATIENTS, MATERIALS, AND METHODS: Forty-four patients who underwent endoscopic biopsies for ventricular or paraventricular tumors between 1993 and 2011 were included in the study. Charts and images were reviewed retrospectively to evaluate rates of adverse events, mortality, and tumor cell dissemination. Adverse events, mortality, and tumor cell dissemination were evaluated. RESULTS: Postoperative clinical condition improved in 63.0% of patients, remained stable in 30.4%, and worsened in 6.6%. One patient (2.2%) had a postoperative thalamic stroke leading to hemiparesis and hemineglect. No procedure-related deaths occurred. Postoperative tumor cell dissemination was observed in 14.3% of patients available for follow-up. CONCLUSIONS: For patients presenting with occlusive hydrocephalus due to tumors in or adjacent to the ventricular system, endoscopic CSF diversion is the procedure of first choice. Tumor biopsy in the current study did not affect safety or efficacy.

Neuroendoscopic stent placement for cerebrospinal fluid pathway obstructions in adults.

OBJECTIVE Since its revival in the early 1990s, neuroendoscopy has become an integral component of modern neurosurgery. Endoscopic stent placement for treatment of CSF pathway obstruction is a rarely used and underestimated procedure. The authors present the first series of neuroendoscopic intracranial stenting for CSF pathway obstruction in adults with associated results and complications spanning a long-term follow-up of 20 years. METHODS The authors retrospectively reviewed a prospectively maintained clinical database for endoscopic stent placement performed in adults between 1993 and 2013. RESULTS Of 526 endoscopic intraventricular procedures, stents were placed for treatment of CSF disorders in 25 cases (4.8%). The technique was used in the management of arachnoid cysts (ACs; n = 8), tumor-related CSF disorders (n = 13), and hydrocephalus due to stenosis of the foramen of Monro (n = 2) or aqueduct (n = 2). The mean follow-up was 87.1 months. No deaths or infections occurred that were related to endoscopic placement of intracranial stents. Late stent dislocation or migration was observed in 3 patients (12%). CONCLUSIONS Endoscopic intracranial stent placement in adults is rarely required but is a safe and helpful technique in select cases. It is indicated when reliable and long-lasting restoration of CSF pathway obstructions cannot be achieved with standard endoscopic techniques. In the treatment of tumor-related hydrocephalus, it is a good option to avoid reclosure of the restored CSF pathway by tumor growth. Currently, routine stent placement after endoscopic fenestration of ACs is not recommended. Stent placement for treatment of CSF disorders due to tumor is a good option for avoiding CSF shunting. To avoid stent migration and dislocation, and to allow for easy removal if needed, the device should be fixed to a bur hole reservoir.

August 2001: Sellar/suprasellar mass in a 59-year-old woman.

The August 2001 COM. Symptomatic granular cell tumors (GCTs) of the neurohypophysis are rare lesions. They are generally regarded as benign neoplasms, although detailed descriptions of the natural course of the tumors are limited to a few cases. We report on a 59-year-old woman with a large GCT of the neurohypophysis and rapid onset of symptoms. Although lacking definitive signs of malignancy, the tumor showed nuclear polymorphism, proliferative activity, evidence of a mutation of the tumor suppressor gene p53 as well as expression of the apoptosis-inhibiting protein bcl-2. These indices may be useful in defining more precisely the clinicopathological prognosis for neurohypophyseal GCTs.

Intraventricular infusion of the neurotrophic protein S100B improves cognitive recovery after fluid percussion injury in the rat.

Elevated serum S100B levels have been shown to be a predictor of poor outcome after traumatic brain injury (TBI). Experimental data, on the other hand, demonstrate a neuroprotective and neurotrophic effect of this calcium-binding protein. The purpose of this study was to examine the role of increased S100B levels on functional outcome after TBI. Following lateral fluid percussion or sham injury in male Sprague Dawley rats (n = 56), we infused S100B (50 ng/h) or vehicle into the cerebrospinal fluid of the ipsilateral ventricle for 7 days using an osmotic mini-pump. Assessment of cognitive performance by the Morris water maze on days 30-34 after injury revealed an improved performance of injured animals after S100B infusion (p < 0.05), when compared to vehicle infusion. Blood samples for analysis of clinical markers of brain damage, S100B and neuron specific enolase, taken at 30 min, 3 h, 4 h, 2 days, or 5 days showed a typical peak 3 h after injury (p < 0.01), and higher serum levels correlated significantly with an impaired cognitive recovery (p < 0.01). The correlation of higher serum S100B levels with poor water maze performance may result from injury induced opening of the blood-brain barrier, allowing the passage of S100B into serum. Thus while higher serum levels of S100B seem to reflect the degree of blood-brain barrier opening and severity of injury, a beneficial effect of intraventricular S100B administration on long-term functional recovery after TBI has been demonstrated for the first time. The exact mechanism by which S100B exerts its neuroprotective or neurotrophic influence remains unknown and needs to be elucidated by further investigation.

Endoscopic resection of colloid cysts.

COLLOID CYSTS OFTEN cause cerebrospinal fluid pathway obstruction, which results in ventricular enlargement that provides sufficient space for endoscopy. Because of further improvement of endoscopic instrumentation and hemostasis, colloid cysts often can be resected completely via an endoscopic approach. This article describes our endoscopic technique as developed for the removal of colloid cysts located in the third ventricle.

Investigations using magnetic resonance imaging: is neurovascular compression present in patients with essential hypertension?

OBJECT: A possible relationship between neurovascular compression of the rostral ventrolateral medulla oblongata (RVLM) and essential hypertension is investigated using a specifically designed magnetic resonance (MR) imaging method. In conjunction with the ninth and 10th cranial nerves, baroreceptor afferents enter the RVLM, which represents a crucial relay for regulation of autonomic blood pressure. In 1985 Jannetta and coworkers proposed a causal relationship between essential hypertension and intraoperatively observed neurovascular compression of the left RVLM. METHODS: Currently, MR imaging is the method of choice for the assessment of neurovascular relationships at the brainstem. By obtaining axial images of a thin-slice turbo inversion-recovery sequence and three-dimensional time-of-flight MR angiograms (fast imaging with steady-state precision), the authors documented the occurrence of neurovascular contacts with the RVLM at the level of the root entry zones (REZs) of the ninth and 10th cranial nerves in 25 patients with essential hypertension, 30 normotensive volunteers, and 10 patients with renal hypertension. Neurovascular contacts with the REZ at the left RVLM were found in 32% of patients with essential hypertension, 37% of normotensive volunteers, and 20% of patients with renal hypertension. In total, neurovascular contacts on either side of the RVLM were documented in 68% of patients with essential hypertension, 53% of normotensive volunteers, and 50% of patients with renal hypertension. CONCLUSIONS: The results do not support the theory of neurovascular compression in cases of essential hypertension. Findings of neurovascular contacts on MR images are not indications for decompression surgery. For further clarification, however, prospective MR imaging studies should be considered in young patients with essential hypertension in whom the history of high blood pressure is short.