Morphometry of the anterior third ventricle region as a guide for the subfrontal (translaminaterminalis) approach

The anterior third ventricle region acquires clinical significance in benign and malignant tumors and cyst formations, of which craniopharyngiomas and gliomas are the most common. The subfrontal approach is one of the most preferred approaches for removing these tumors. In this study, the microsurgical anatomy of 81 Turkish, adult cadaveric hemispheres was examined to provide morphometric data of the region. These measurements from the anterior third ventricle region serve as a guide for neurosurgeons during surgical approach for removing anterior third ventricle tumors.     

Conservative (labyrinth-preserving) transpetrosal approach to the clivus and petroclival region – indications,complications, results and lessons learned

Objective. Tumours or vascular lesions of the clivus and juxtaclival region present a unique challenge to neurosurgeons and a variety of techniques, with a wide spectrum of complexity, have been advocated. This report presents the use of a conservative transpetrosal approach which combines partial removal of the postero-lateral petrous bone with preservation of the labyrinth, with particular focus on efficacy and the reduction of complications. Patients and methods. Over 9 years, 52 patients underwent a conservative combined supra-infratentorial, labyrinth-preserving transpetrosal approach. There were 32 women and 20 men; 33 had tumour lesions including 22 patients with a clival or petroclival meningioma. Among the 19 patients with a vascular lesion, 12 patients had a basilar artery trunk aneurysm, including one giant midbasilar aneurysm. 3 Patients had vertebro-basilar junction aneurysms, and 4 patients had a pontine cavernoma. Data on the clinical features, investigations and operative techniques were extracted from the patients case records. Outcome was assessed by serial examinations of the patients or by telephone interview with the treating physician, and in survivors graded as excellent, good or poor. Results. 52 patients, 23 patients (44%) had an excellent outcome, in 21 patients (41%) the outcome was good and in 7 patients (13%) the outcome was poor. One patient with a complex fusiform basilar trunk aneurysm, operated upon as an emergency, died in the postoperative period. Total resection was achieved, as demonstrated by follow-up MRI in 20 of 33 patients with a tumour, including 15 of 22 patients with clival or petro-clival meningiomas. All vascular lesions were treated effectively and in 14 patients with a basilar or vertebro-basilar junction aneurysm, clipping of the aneurysm was achieved. In one patient, a giant calcified vertebro-basilar junction aneurysm was resected. New cranial nerve deficits or an accentuation of a pre-existing deficit, occured in 8 patients with a tumour and 4 patients with a vascular lesion. Complications included: temporary conductive hearing deficit in 4 patients, a minor laceration of the sigmoid/transverse sinus in 4 and transient post-operative CSF leakage in 12 patients. Temporary lumbar drainage resulted in sealing of the CSF leak in 8 patients, but in 3 patients a permanent ventriculo-peritoneal shunt had to be implanted. Conclusion. When based on adequate experience in skull base surgery, the combined supra-infratentorial, conservative transpetrosal approach, with preservation of the labyrinth, allows direct and wide exposure of a large variety of tumour and vascular lesions located along the supra- and infratentorial juxta-clival area; little or almost no retraction of neurovascular structures is needed and with adherence to important principles, complications related to the approach can be minimised.Published online July 23, 2003     

Large sphenocavernous meningiomas: Is there still a role for the intradural approach via the pterional-transsylvian route?

Summary.  Background: Large-sized sphenocavernous meningiomas represent a surgical challenge. Although the role of skull base techniques with combined extra- and intradural steps has been recently emphasized, pure intradural resection tactics via the pterional route constitute the traditional microsurgical approach for resection of such tumours.  Method: We report the application of the pterional-transsylvian approach in 13 patients with sphenocavernous meningiomas. This series is unique because it includes only patients with tumours exceeding 5 cm in their greatest dimension.  Findings: A gross total resection was accomplished in 10 patients (77%). Eight patients had a good outcome, one had a persistent mild hemiparesis, and one died. No recurrences occurred in this group. Three patients (23%) had subtotal resections owing to invasion of the cavernous sinus in one instance and encasement of the middle cerebral artery in the others. Two had a good outcome and one died. In these patients minimal asymptomatic tumour progression was seen 3 and 6 years after surgery. The overall surgical outcome was good in 10 patients (77%), fair in one, and death in two.  Interpretation: In our experience, large sphenocavernous meningiomas may be operated on adopting pure intradural resection tactics via the pterional-transsylvian route with rates of gross total removal and surgical complications related to brain retraction or vascular manipulation comparable to those of extensive skull base approaches. The traditional intradural pterional transsylvian approach continues to have a place in the treatment of these lesions. Published online April 28, 2003 RID="*" ID="*"  This paper was supported in part by Grant “Piano B008 – P.R. 2” from M.U.R.S.T. and European Community.  Correspondence: Domenico d'Avella, M.D., Neurosurgical Clinic, Department of Neuroscience, Psychiatric and Anesthesiolgical Sciences, Policlinico Universitario, via Consolare Valeria 1, 98122 Messina, Italy.     

Iranian migrants' discourses of health and the implications for using standardized health measures with minority groups

This paper explores the concept of health implied in the SF-36 within a group of Iranians in Australia. Qualitative data were collected from a sample of 21 people—10 females and 11 males. For the first time, the NUD*IST program was used to organize and manage the data in Persian (also known as Farsi), the language spoken by Iranians. Health was defined in terms of holistic, spiritual, social, physical/emotional aspects, and absence-of-disorder dimensions. Among these, physical, absence of disorder, holistic, and spiritual aspects of health were mentioned more frequently than other themes. The findings of the study raise concerns about the extent to which the SF-36 captures the diversity of the concept of health as expressed by the sample of Iranian migrants.     

Lateral approach to the sciatic nerve in the popliteal fossa: a comparison between 1.5% mepivacaine and 0.75% ropivacaine

BACKGROUND AND OBJECTIVES: Ropivacaine and mepivacaine are commonly used local anesthetics for peripheral nerve blockade. The purpose of the present study was to compare onset time, quality of anesthesia, and duration of analgesia with ropivacaine 0.75% and mepivacaine 1.5% for lateral popliteal nerve block. METHODS: Fifty American Society of Anesthesiologists (ASA) physical status I or II patients scheduled for foot and ankle surgery with calf tourniquet under lateral popliteal sciatic nerve block were randomly assigned to receive 30 mL of either ropivacaine 0.75% or mepivacaine 1.5%. Time required for onset of sensory and motor block, resolution of motor blockade, onset of postsurgical pain, and time of first analgesic medication were recorded. RESULTS: The 2 groups were similar with regard to demographic variables and duration of surgery. Onset of sensory and motor block was significantly shorter in the mepivacaine group (9.9 +/- 3.3 min and 14.7 +/- 3.6 min, respectively) than in the ropivacaine group (18.1 +/- 6.1 min and 23.6 +/- 5.5 min, respectively) (P < 0.001). Resolution of motor block occurred later in the ropivacaine group than in the mepivacaine group (P < 0.001), and duration of postoperative analgesia was significantly longer in the ropivacaine group (19 +/- 3.4 h) compared with the mepivacaine group (5.9 +/- 1.1 h) (P < 0.001). Analgesic requirements were higher in mepivacaine group than in the ropivacaine group (P < 0.001). There were 2 failed blocks, one in each group. CONCLUSIONS: Both ropivacaine and mepivacaine provided effective sciatic nerve blockade. Mepivacaine 1.5% displayed a significantly shorter onset time than ropivacaine 0.75%. Postoperatively, ropivacaine 0.75% resulted in longer-lasting analgesia and less need for oral pain medication.     

Preshaping and continuous evolution of motor cortical representations during movement preparation

While a goal-directed movement is prepared, motor cortical neurons selectively change their activity in relation to prior information about movement direction. Only little is known, however, about the neuronal representation of partial information about this parameter. We investigated this question by training monkeys in a multidirectional centre-out pointing task. A preparatory signal provided prior information about one, two or three possible adjacent targets, thus manipulating the level of certainty about movement direction. After a 1-s delay, the response signal specified one of the precued targets to indicate the actual movement to be performed. Based on the directional tuning curves of individual motor cortical neurons determined during the reaction time interval, we constructed distributions of the population activation (DPAs), which we were then able to estimate as well during the preparatory period. We found that these distributions were preshaped by prior information, with peaks of activation centred over the range of precued movement directions. These peaks sharpened as the response signal approached, and shifted to the specified movement direction subsequent to that signal. Wider ranges of precued movement directions were represented by broader DPAs. Trials in which monkeys produced short reaction times were characterized by narrower distributions than trials with long reaction times. Our study thus provides evidence for (i) a graded preshaping of the neuronal population representation of movement direction by partial information about this parameter, and (ii) the continuous evolution of the preshaped population representation during the preparatory period towards movement initiation.     

Diagnosis and treatment of juvenile nasopharyngeal angiofibroma

The aim of this retrospective study was to compare clinical and radiological findings and discuss optimal surgical approach in patients with juvenile nasopharyngeal angiofibroma (JNA). Forty-three cases of JNA were treated at our institution from 1975 to 1999. Thirty-three male patients aged between 8 and 25 years (mean 15.3) were included. Twenty-nine patients underwent primary surgical treatment at our institution and four were treated for recurrence following primary surgery elsewhere. Tumors were staged according to Fisch’s staging. Preoperative embolization was performed in 22 cases. Surgical techniques consisted of the transantral approach, lateral rhinotomy approach, transmaxillary via midfacial degloving approach, and the subtemporal preauricular infratemporal fossa approach. Tumors were classified stage I in seven cases, stage II in 11, stage III in 13 and stage IV in two. The mean delay between the initial symptom and surgery was 14 months overall, 18 months for stage I, 14 for stage II, 13 for stage III and 12 for stage IV. The transantral approach was used in 11 patients, lateral rhinotomy approach in 11 cases, transmaxillary via midfacial degloving approach in three patients, and pre-auricular infra-temporal approach in eight patients. Mean follow-up after surgery was 56 months. Six patients had recurrent tumors. Surgery is the gold standard for treatment of JNA. Modern imaging techniques allow accurate diagnosis and staging of JNA. Our experience and a review of the literature shows that the surgical approach should be selected according to tumor stage. Received: 18 December 2000 / Accepted: 5 February 2001     

Temporal approach for resection of juvenile nasopharyngeal angiofibromas

OBJECTIVE: To describe a lateral preauricular temporal approach for resection of juvenile nasopharyngeal angiofibroma (JNA). STUDY DESIGN: A retrospective review of five patients with JNA tumors that were resected by a lateral preauricular temporal approach. METHODS: The medical records of five patients who underwent resection of JNA tumors via a lateral preauricular temporal approach were reviewed, and the following data collected: tumor extent, blood loss, hospital stay, and surgical complications. RESULTS: Five patients with JNA tumors had resection by a lateral preauricular temporal approach. These tumors ranged from relatively limited disease to more extensive intracranial, extradural tumors. Using the staging system advocated by Andrews et al., these tumors included stages II, IIIa, and IIIb. Four patients (stages II, IIIa, IIIa, and IIIb) who underwent primary surgical excision had minimal blood losses and were discharged on the first or third postoperative day with minimal transient complications (mild trismus, frontal branch paresis, serous effusion, and cheek hypesthesia). The remaining patient (stage IIIb) did well after surgery, despite having undergone preoperative radiation therapy and sustaining a significant intraoperative blood loss. There have been no permanent complications or tumor recurrences. CONCLUSIONS: A lateral preauricular temporal approach to the nasopharynx and infratemporal fossa provides effective exposure for resection of extradural JNA tumors. The advantages of this approach include a straightforward route to the site of origin, the absence of facial and palatal incisions, and avoidance of a permanent ipsilateral conductive hearing loss.     

Resection of cancer of the tongue base and tonsil via the transhyoid approach

OBJECTIVE: To assess whether transhyoid resection of the tongue base and tonsil lesions is an effective approach to tumors involving this region compared with more traditional anterior surgical approaches that arbitrarily involve either segmental resection or division of the mandible. STUDY DESIGN: Retrospective review. METHODS: Since 1988, we have used a combined transhyoid and transoral approach to resect lesions involving the tongue base, tonsil, or both. Forty-one patients were identified who underwent surgical resection of lesions involving this region via this combined approach during this period. A stage-matched group of 41 patients was also identified in which patients underwent resection via traditional composite or mandibulotomy approaches and was used as a basis for comparison. Factors assessed included status of surgical margins, postoperative complications, degree of postoperative dysphagia, and long-term outcome. RESULTS: Comparison between the two groups revealed similar rates of negative surgical margins. Levels of postoperative dysphagia, notably severe primarily in patients with either T4 or recurrent disease, were also similar between groups. Complication rates, especially with regard to fistula occurrence and mandible-healing problems, were significantly lower in the transhyoid group. Analysis of long-term outcome revealed similar patterns with regard to disease status in both groups. CONCLUSIONS: The combined transhyoid and transoral approach is an effective surgical option for a number of lesions affecting the tongue base, tonsil, or both. Although similar to other approaches with regard to postoperative function and disease outcome, the transhyoid approach is associated with decreased postoperative morbidity. However, tumors that extend to involve the mandible or pterygoid musculature or skull base are probably best suited for traditional approaches that involve division of the mandible.     

新生大鼠海马的显微手术入路

目的研究最大程度暴露新生大鼠海马的手术入路。方法采用经颞外侧、大脑纵裂、小脑幕上缘大脑纵裂联合3种入路暴露新生大鼠海马。结果分析3种入路优缺点,经小脑幕上缘大脑纵裂联合入路的方法简便、容易掌握,且最大程度上暴露了海马的全部结构。结论新生大鼠海马最大程度显微暴露为神经干细胞研究提供必备平台。