The endoscopic endonasal eustachian tube anterolateral mobilization strategy: minimizing the cost of the extreme-medial approach.

OBJECTIVE: The ventral jugular foramen and the infrapetrous region are difficult to access through conventional lateral and posterolateral approaches. Endoscopic endonasal approaches to this region are obstructed by the eustachian tube (ET). This study presents a novel strategy for mobilizing the ET while preserving its integrity. Qualitative and quantitative comparisons with previous ET management paradigms are also presented. METHODS: Ten dry skulls were analyzed. Four ET management strategies were sequentially performed on a total of 6 sides of cadaveric head specimens. Four measurement groups were generated: in group A, the ET was intact and not mobilized; in group B, the ET was mobilized inferolaterally; in group C, the ET underwent anterolateral mobilization; and in group D, the ET was resected. ET range of mobilization, surgical exposure area, and surgical freedom were measured and compared among the groups. RESULTS: Wide exposure of the infrapetrous region and jugular foramen was achieved by removing the pterygoid process, unroofing the cartilaginous ET up to the level of the posterior aspect of the foramen ovale, and detaching the ET from the skull base and soft palate. Anterolateral mobilization of the ET facilitated significantly more retraction (a 126% increase) of the ET than inferolateral mobilization (mean ± SD: 20.8 ± 11.2 mm vs 9.2 ± 3.6 mm [p = 0.02]). Compared with group A, groups C and D had enhanced surgical exposure (142.5% [1176.9 ± 935.7 mm2] and 155.9% [1242.0 ± 1096.2 mm2], respectively, vs 485.4 ± 377.6 mm2 for group A [both p = 0.02]). Furthermore, group C had a significantly larger surgical exposure area than group B (p = 0.02). No statistically significant difference was found between the area of exposure obtained by ET removal and anterolateral mobilization. Anterolateral mobilization of the ET resulted in a 39.5% increase in surgical freedom toward the exocranial jugular foramen compared with that obtained through inferolateral mobilization of the ET (67.2° ± 20.5° vs 48.1° ± 6.7° [p = 0.047]) and a 65.4% increase compared with that afforded by an intact ET position (67.2° ± 20.5° vs 40.6° ± 14.3° [p = 0.03]). CONCLUSIONS: Anterolateral mobilization of the ET provides excellent access to the ventral jugular foramen and infrapetrous region. The surgical exposure obtained is superior to that achieved with other ET management strategies and is comparable to that obtained by ET resection.

Comparison between posterior lumbar fusion with pedicle screws and posterior lumbar interbody fusion with pedicle screws in adult spondylolisthesis.

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.

Comparison between posterior lumbar fusion with pedicle screws and posterior lumbar interbody fusion with pedicle screws in adult spondylolisthesis

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.

O objetivo foi comparar dois grupos de pacientes portadores de espondilolistese lombar que foram submetidos a dois procedimentos cirúrgicos distintos, avaliando os resultados clínicos levando em consideração a qualidade de vida. Durante o período de 1998 a 2001 sessenta pacientes portadores de espondilolistese da coluna lombar ístmica e degenerativa foram submetidos a tratamento cirúrgico no Hospital Biocor em Belo Horizonte, por um mesmo cirurgião foram analisados prospectivamente. Os primeiros trinta pacientes foram submetidos a fusão posterior com parafusos pediculares e os trinta seguintes a fusão posterior com parafusos pediculares associada a fusão intersomática posterior. Os pacientes foram submetidos a liberação radicular com laminectomia e foraminotomia. A avaliação clínica foi feita utilizando as escalas de Prolo Econômico e Funcional, o questionário de Rolland-Morris e de Oswestry. Os resultados clínicos apresentaram que os dois procedimentos realizados foram eficazes. Houve maior número de complicações relacionadas com a biomecânica no grupo que foi submetido somente à fusão posterior e o grupo submetido à fusão posterior associada a fusão intersomática apresentou melhores resultados com retorno as atividades diárias e melhora da qualidade de vida.

The radical transbasal approach for resection of anterior and midline skull base lesions.

OBJECT: Craniofacial surgery can be performed to treat midline and anterior skull base lesions by creating a bicoronal scalp incision without the need for an additional transfacial procedure. Originally described as the transbasal approach, several modifications for further exposure of the skull base have been described. The authors present data on the application and outcomes of a modified transbasal approach. The radical transbasal approach consists of a bifrontal craniotomy and a frontoorbitonasal osteotomy. METHODS: Between 1992 and 2002, 41 patients (28 male and 13 female patients with a mean age of 38.3 years [range 7-77 years]) underwent 44 radical transbasal procedures. Twenty-three malignant and 18 benign lesions involving the midline skull base were treated. These cases were reviewed retrospectively. Gross-total resection of 30 lesions was achieved. Seven lesions were resected subtotally and six partially; one lesion was debulked. Complications occurred in 26 (59.1%) of the 44 operations and mostly consisted of cerebrospinal fluid leakage. The surgery-related mortality rate was 6.8% (three patients). Based on their pre- and postoperative Karnofsky Performance Scale scores, 86.4% of patients improved or remained the same. CONCLUSIONS: The radical transbasal approach increases the midline craniofacial corridor by allowing the globes to be safely retracted laterally. It also enhances exposure of the maxillary sinus from above. The morbidity and mortality rates associated with this procedure are high but consistent with the known rates for craniofacial surgery. This approach is best suited for the treatment of anterior skull base tumors that extend into the nasal cavity, orbit, ethmoid sinus, nasopharynx, and upper clivus. The approach may allow resection of tumors involving the maxillary sinus area without the need for an additional transfacial approach.

Exposure of midline cranial base without a facial incision through a combined craniofacial-transfacial procedure.

OBJECTIVE: A single-stage combined craniofacial-transfacial approach that exposes the midline cranial base without visible facial incisions is described. METHODS: Between 1992 and 1998, eight patients underwent surgery for five different anterior cranial base pathological findings: four angiofibromas, one mesenchymal chondrosarcoma, one esthesioneuroblastoma, one odontogenic myxoma, and one encephalocele. In all cases, the surgical exposure consisted of a bicoronal scalp incision with a bifrontal craniotomy and fronto-orbitonasal osteotomy, and then a sublabial incision for transmaxillary exposure. RESULTS: Gross total resection was achieved in five cases. The encephalocele was resected with complete reconstruction of the bony defect. Seven patients developed complications, primarily wound infections, cerebrospinal fluid leaks, and anemia. Postoperative Karnofsky Performance Scale scores ranged between 80 and 100 (mean, 92.5). Long-term follow-up information (mean, 56 mo; median, 59.5 mo; range, 5-108 mo) was available for all patients. CONCLUSION: Large anterior cranial base lesions can be resected and excellent cosmetic outcomes can be achieved with a single-stage combined transfacial-craniofacial approach that exposes the entire midline cranial base and requires no facial incisions.

Salvage of advanced squamous cell carcinomas of the head and neck: internal carotid artery sacrifice and extracranial-intracranial revascularization.

OBJECT: Squamous cell carcinoma (SCC) of the head and neck may involve the carotid artery (CA) in the neck or skull base. Whether tumor resection should be associated with sacrifice of the CA is debatable. METHODS: Records obtained in five consecutive patients (three men, and two women; mean age 58 years, range 47-69 years) treated for recurrent or progressive SCC involving the internal carotid artery (ICA) at the skull base were reviewed retrospectively. The ICA was sacrificed, an extracranial-intracranial (EC-IC) bypass was performed using a saphenous vein graft, and the tumor and involved ICA segment were resected. Gross-total resection of the SCC was achieved in four cases. One patient died of an acute postoperative stroke due to bypass occlusion and did not undergo tumor resection. No other permanent ischemic or neurological deficits were noted. The other four patients died of tumor progression (survival range 2-40 months, mean 14 months). One patient survived for more than 2 years (2-year overall survival rate 20%). Histological tumor invasion of the CA wall was verified in one of the three evaluated specimens. CONCLUSIONS: A high rate of morbidity and mortality is associated with cases in which skull base CA sacrifice and an EC-IC bypass are performed. Not all resected arteries are shown to have malignant infiltration on histological examination. Better preoperative imaging criteria are needed to define malignant infiltration of the ICA at the skull base. Chemotherapy and radiotherapy without aggressive tumor resection may be an option for these patients.

Interactive stereoscopic virtual reality: a new tool for neurosurgical education. Technical note.

The goal of this study was to develop a new method for neurosurgical education based on interactive stereoscopic virtual reality (ISVR). Interactive stereoscopic virtual reality can be used to recreate the three-dimensional (3D) experience of neurosurgical approaches much more realistically than standard educational methods. The demonstration of complex 3D relationships is unrivaled and easily combined with interactive learning and multimedia capabilities. Interactive stereoscopic virtual reality permits the accurate recreation of neurosurgical approaches through integration of several forms of stereoscopic multimedia (video, interactive anatomy, and computer-rendered animations). The content explored using ISVR is obtained through a combination of approach-based cadaver dissections, live surgical images and videos, and computer-rendered animations. These media are combined through an interactive software interface to demonstrate key aspects of a neurosurgical approach (for example, patient positioning, draping, incision, individual surgical steps, alternative steps, relevant anatomy). The ISVR platform is designed for use on a desktop personal computer with newly developed, inexpensive, platform-independent shutter glasses. Interactive stereoscopic virtual reality has been used to capture the anatomy and methods of several neurosurgical approaches. In this paper the authors report their experience with ISVR and describe its potential advantages. The success of a neurosurgical approach is contingent on the mastery of complex, 3D anatomy. A new technology for neurosurgical education, ISVR can improve understanding and speed the learning process. It is an effective tool for neurosurgical education, bridging the substantial gap between textbooks and intraoperative training.

Black holes of the brain: how to reach challenging areas of the cerebrum.

Numerous techniques and tools can be used to access difficult areas of the cerebrum: skull base techniques, modern operating room equipment, and a unified team approach. Using these principles, challenging areas of the cerebrum can be approached with maximal success and minimal morbidity. These techniques are powerful tools in the armamentarium of neurosurgeons and can improve any neurosurgical approach. The basilar region remains one of the most difficult areas to approach. Despite its inherent complexity, lesions of the basilar region can be treated successfully. The far-lateral approach is used to access the lower two-fifths of the basilar region; the transcochlear approach is used to access the middle fifth of the basilar region; and the orbitozygomatic approach is used to access the upper two-fifths of the basilar region. Each approach beautifully exemplifies the principles of skull base surgery.

Aspectos tecnicos e resultados do bypass de alto fluxo com veia safena para aneurismas complexos / Saphenous vein high-flow bypass for complex aneurysms: technical aspects and surgical results

A tecnica de reconstrucao vascular com ponte venosa de alto fluxo para aneurismas cerebrais complexos é apresentada. As indicacoes, complicacoes e resultados de uma serie de 27 pacientes operados no periodo de 1992 a 1997 sao discutidos. Do total de pacientes 71 por cento possuiam aneurismas gigantes da arteria carotida interna intracavernosa. Cinco pacientes foram submetidos a pontes venosas como medida de profilaxia contra isquemia transoperatoria (bypass profilatico) no tratamento de aneurismas gigantes supraclinoideos. Obtivemos 75 por cento de patencia nos enxertos apos controle angiografico. Nossos resultados mostraram-se bons em 85,7 por cento dos pacientes; nossa morbidade isquemica foi de 3,6 por cento e nossa morbidade nao-isquemica de 7,1 por cento a mortalidade na serie foi de 3,6 por cento.