Search PubMed⌕ Search

Biomedical subjects

Robert F Spetzler

Publications and source records attributed to Robert F Spetzler.

96 records · Page 6Linked to original sources

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review.

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.

Adult↗

Modified classification of spinal cord vascular lesions.

The literature on spinal vascular malformations contains a great deal of confusing terminology. Some of the nomenclature is inconsistent with the lesions described. Based on the experience of the senior author (R.F.S.) in the treatment of more than 130 spinal cord vascular lesions and based on a thorough review of the relevant literature, the authors propose a modified classification system for spinal cord vascular lesions. Lesions are divided into three primary or broad categories: neoplasms, aneurysms, and arteriovenous lesions. Neoplastic vascular lesions include hemangioblastomas and cavernous malformations, both of which occur sporadically and familially. The second category consists of spinal aneurysms, which are rare. The third category, spinal cord arteriovenous lesions, is divided into arteriovenous fistulas and arteriovenous malformations (AVMs). Arteriovenous fistulas are subdivided into those that are extradural and those that are intradural, with intradural lesions categorized as either dorsal or ventral. Arteriovenous malformations are subdivided into extradural-intradural and intradural malformations. Intradural lesions are further divided into intramedullary, intramedullary-extramedullary, and conus medullaris, a new category of AVM. This modified classification system for vascular lesions of the spinal cord, based on pathophysiology, neuroimaging features, intraoperative observations, and neuroanatomy, offers several advantages. First, it includes all surgical vascular lesions that affect the spinal cord. Second, it guides treatment by classifying lesions based on location and pathophysiology. Finally, it eliminates the confusion produced by the multitude of unrelated nomenclatural terms found in the literature.

Aneurysm↗

Working area and angle of attack in three cranial base approaches: pterional, orbitozygomatic, and maxillary extension of the orbitozygomatic approach.

OBJECTIVE: This study was designed to quantify the operative exposure obtained in the pterional, orbitozygomatic, and modified orbitozygomatic with maxillary extension surgical approaches. METHODS: The pterional and orbitozygomatic approaches and a variation of the orbitozygomatic osteotomy that included an extra centimeter of bone resection in the inferior direction ("maxillary extension") were performed on cadaveric heads. For each surgical exposure, the working area was determined by using triangles defined with anatomic points. The "angle of attack" of the approaches for the same target point was determined with the use of a robotic microscope. RESULTS: The maximum allowable angle of attack was significantly greater with the orbitozygomatic approach (37.2 +/- 4.7 degrees) than that with the pterional approach (27.1 +/- 4.3 degrees) (P < 0.001). The angle of attack with the maxillary extension (42.0 +/- 4.9 degrees) was significantly greater than that with the orbitozygomatic approach (P < 0.001). The working areas were 281, 343, and 371 mm(2) for the pterional, orbitozygomatic, and maxillary extension approaches, respectively. The orbitozygomatic approach with maxillary extension had a significantly larger working area than the pterional approach (P = 0.011). CONCLUSION: Increments in bony removal open a wider angle in which to work more than they increase the actual amount of working area. Increasing the amount of bone removed by using an orbitozygomatic approach instead of a pterional approach converts a narrow space into a wide portal, allowing surgeons to work closer to the surgical target while decreasing the need for brain retraction. Extending the orbitozygomatic approach into the maxillary region also improves the exposure area and angle, but less significantly.

Cadaver↗

Effects of three-dimensional angiography on the coiling of cerebral aneurysms.

OBJECTIVE: To assess how information acquired with three-dimensional angiography (3DA) affects the endovascular management of cerebral aneurysms. METHODS: The role of 3DA in 50 aneurysm cases was assessed with respect to five predetermined factors, i.e., whether 3DA facilitated treatment, modified the coil embolization technique, made treatment unnecessary or unjustified by revealing new information, suggested a potential treatment failure or complication, or did not contribute to endovascular management. RESULTS: Findings for a total of 46 patients with 50 aneurysms who underwent 3DA in the course of their endovascular treatment were analyzed. Overall, 3DA facilitated coiling in 25 cases, modified the treatment technique in 11 cases, eliminated the need for treatment in 9 cases, and suggested a potential treatment complication in 5 cases. 3DA was deemed useful in the management of all cases, and in no case was its use associated with a complication. Specifically, 3DA facilitated treatment by delineating the optimal fluoroscopic tube angulation for coiling, modified treatment by revealing anatomic characteristics that would require balloon remodeling or stent assistance, obviated treatment by excluding the possibility of an aneurysm or by identifying unfavorable anatomic features, and predicted a treatment complication by revealing an associated vessel that was likely to be compromised with coiling of the aneurysm. CONCLUSION: 3DA enhances our ability to treat aneurysms endovascularly. Most importantly, aneurysm treatment may be facilitated, modified, or proven unnecessary because of vital information obtained with 3DA.

Adult↗

Intracranial aneurysm surgery in Ehlers-Danlos syndrome Type IV.

OBJECTIVE: Ehlers-Danlos syndrome Type IV is a heritable connective tissue disorder with frequent neurovascular manifestations, such as intracranial aneurysms. Patients with this syndrome have notoriously fragile blood vessels, and the reported mortality rate for any type of vascular surgical procedure is 40%. This syndrome is rare, however, and the complication rate of aneurysm surgery may have been overestimated. METHODS: We reviewed our experience with aneurysm surgery in a group of patients with Ehlers-Danlos syndrome Type IV. RESULTS: The patient population consisted of three women and one man with a mean age of 44 years (age range, 20-57 yr). One patient, who had a ruptured anterior circulation aneurysm, died as a direct result of surgery because of marked vascular fragility. Three patients underwent successful surgery, consisting of a craniotomy and clipping of a ruptured anterior circulation aneurysm in two patients and a craniotomy and clip ligation of the parent artery in one patient with a ruptured dissecting vertebral artery aneurysm. Intraoperatively, mild vascular or connective tissue fragility was commonly observed. Postoperative complications (e.g., spontaneous pneumothorax and vertebral artery dissection) also were common but did not result in permanent morbidity. CONCLUSION: The risk of neurovascular surgery is high in patients with Ehlers-Danlos syndrome Type IV and intra- and postoperative complications are common. However, most patients tolerate the operation without permanent morbidity.

Adult↗

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.

Brain↗