H. Hunt Batjer and Duke S. Samson
✓ Giant paraclinoidal carotid artery aneurysms frequently require temporary interruption of local circulation to facilitate safe occlusion. Due to brisk retrograde flow through the ophthalmic artery and cavernous branches, simple trapping of the aneurysm by cervical internal carotid artery clamping and intracranial distal clipping may not adequately soften the lesion. The authors describe a retrograde suction method of aspiration of this collateral supply which they have used in over 40 cases. After temporary trapping, a No. 18 angiocatheter is inserted into the cervical internal carotid artery. This catheter is then connected to a wall suction point allowing rapid aneurysm deflation. This technique, accomplished by the surgical assistant, permits the surgeon the freedom to use both hands in dealing quickly with the aneurysm.
Hunt Batjer and Duke Samson
✓ Only about 5% of intracranial arteriovenous malformations (AVM's) are located predominantly within the ventricular system. Between July, 1981, and February, 1986, 15 patients were treated at the authors' institution for AVM's within the ventricular trigone. The mean age of this patient population was 24 years, and two-thirds were female. Intracranial hemorrhage was by far the most frequent presenting symptom and intraventricular hemorrhage occurred in 11 cases, with multiple episodes being documented in five. Arterial supply of the malformations was quite uniform, with the lateral posterior choroidal or posterior temporal branch of the posterior cerebral artery (PCA) being the most frequent source. Venous drainage was similarly stereotypic, with predominant outflow into the galenic system in all but one patient. An interhemispheric surgical approach was used in eight patients, a middle or inferior temporal gyrus incision was performed in six, and a subtemporal route was chosen in a single patient. Operative results suggest that these lesions can be removed with reasonable safety. An interhemispheric approach is recommended if the nidus projects medially from the trigone and is observed medial to the P2-P3 junction of the PCA on angiography. A middle temporal gyrus approach is suggested if the nidus is lateral to the P2-P3 junction, even when the lesion is located in the dominant hemisphere. A subtemporal approach should be reserved for inferiorly projecting AVM's with cortical representation on the fusiform or parahippocampal gyrus in the nondominant hemisphere.
Clinical presentation, diagnostic evaluation, and surgical treatment
Hunt Batjer and Duke Samson
✓ Infratentorial arteriovenous malformations (AVM's) represent only 5% to 1% of all AVM's in major series. Since 1977, 32 patients with intracranial intradural malformations of the brain stem or cerebellum have been evaluated at the University of Texas Health Science Center, 30 of whom underwent surgical treatment. Twenty-three patients presented with intracranial hemorrhage, which was recurrent in 11 cases, and nine patients were evaluated for progressive brain-stem or cerebellar deficits. A history of progressive deficits was unusual in the group that presented with hemorrhage, and a prior or subsequent hemorrhage was rare in the patients initially evaluted for progressive deficits. Seventeen of these AVM's were located in the vermis, seven within the cerebellar hemisphere, two in the tonsil, two in the cerebellopontine angle, and four within the brain stem. Operative intervention was directed at primary resection in 15 cases, staged resection in seven, embolization and resection in five, and evacuation of hematoma in three. Operative mortality in this surgical series was 7%, with significant morbidity in 13%. Use of modern microsurgical techniques in removal of posterior fossa AVM's may offer results better than the natural history of the disease process, especially in patients who present with hemorrhage.
Bruce Mickey, Lanny Close, Steven Schaefer and Duke Samson
✓ A variety of neoplasms involve both the infratemporal fossa and the base of the middle cranial fossa, in medial proximity to the cavernous sinus and orbital apex. To provide simultaneous access to both the intracranial and extracranial aspects of these tumors, a temporal or frontotemporal craniotomy may be combined with a lateral exposure of the infratemporal fossa. The approach, which is readily achieved by a neurosurgeon and an otolaryngologist acting as a team, involves a unilateral frontotemporal incision extended inferiorly onto the neck, a lateral facial flap reflected anteriorly, and transection of the zygoma followed by its reflection inferolaterally with the temporalis muscle. This exposure provides excellent visualization of both the intradural and extradural aspects of the anterior portion of the cavernous sinus, allowing for an aggressive resection of neoplasms involving this region. Experience with this procedure is reported here in the management of nine patients: three with nasopharyngeal angiofibromas, three with low-grade malignancies of the upper aerodigestive tract, and three with sphenoid ridge meningiomas.
Bruno C. Flores, Jonathan A. White, H. Hunt Batjer and Duke S. Samson
Paraclinoid internal carotid artery (ICA) aneurysms frequently require temporary occlusion to facilitate safe clipping. Brisk retrograde flow through the ophthalmic artery and cavernous ICA branches make simple trapping inadequate to soften the aneurysm. The retrograde suction decompression (RSD), or Dallas RSD, technique was described in 1990 in an attempt to overcome some of those treatment limitations. A frequent criticism of the RSD technique is an allegedly high risk of cervical ICA dissection. An endovascular modification was introduced in 1991 (endovascular RSD) but no studies have compared the 2 RSD variations.
The authors performed a systematic review of MEDLINE/PubMed and Web of Science and identified all studies from 1990–2016 in which either Dallas RSD or endovascular RSD was used for treatment of paraclinoid aneurysms. A pooled analysis of the data was completed to identify important demographic and treatment-specific variables. The primary outcome measure was defined as successful aneurysm obliteration. Secondary outcome variables were divided into overall and RSD-specific morbidity and mortality rates.
Twenty-six RSD studies met the inclusion criteria (525 patients, 78.9% female). The mean patient age was 53.5 years. Most aneurysms were unruptured (56.6%) and giant (49%). The most common presentations were subarachnoid hemorrhage (43.6%) and vision changes (25.3%). The aneurysm obliteration rate was 95%. The mean temporary occlusion time was 12.7 minutes. Transient or permanent morbidity was seen in 19.9% of the patients. The RSD-specific complication rate was low (1.3%). The overall mortality rate was 4.2%, with 2 deaths (0.4%) attributable to the RSD technique itself. Good or fair outcome were reported in 90.7% of the patients.
Aneurysm obliteration rates were similar in the 2 subgroups (Dallas RSD 94.3%, endovascular RSD 96.3%, p = 0.33). Despite a higher frequency of complex (giant or ruptured) aneurysms, Dallas RSD was associated with lower RSD-related morbidity (0.6% vs 2.9%, p = 0.03), compared with the endovascular RSD subgroup. There was a trend toward higher mortality in the endovascular RSD subgroup (6.4% vs 3.1%, p = 0.08). The proportion of patients with poor neurological outcome at last follow-up was significantly higher in the endovascular RSD group (15.4% vs 7.2%, p < 0.01).
The treatment of paraclinoid ICA aneurysms using the RSD technique is associated with high aneurysm obliteration rates, good long-term neurological outcome, and low RSD-related morbidity and mortality. Review of the RSD literature showed no evidence of a higher complication rate associated with the Dallas technique compared with similar endovascular methods. On a subgroup analysis of Dallas RSD and endovascular RSD, both groups achieved similar obliteration rates, but a lower RSD-related morbidity was seen in the Dallas technique subgroup. Twenty-five years after its initial publication, RSD remains a useful neurosurgical technique for the management of large and giant paraclinoid aneurysms.
Duke S. Samson, Richard M. Hodosh and W. Kemp Clark
✓ The natural history of unruptured asymptomatic aneurysms is unclear. Because of this uncertainty regarding risk of ultimate enlargement and/or hemorrhage, and in view of the significant mortality and morbidity traditionally involved in aneurysm surgery, clinicians have varied in their advocacy of surgical management of such lesions. Forty-nine consecutive patients harboring 52 such aneurysms were treated surgically over a 57-month period. There were no surgical deaths and morbidity was within acceptable limits. Patient population characteristics and surgical technique are discussed.
Duke S. Samson and Babu G. Welch
Phillip D. Purdy, H. Hunt Batjer and Duke Samson
✓ Endovascular embolization procedures have undergone dramatic evolution and improvement in recent years. Despite these advances, controversy remains regarding the optimal role of these procedures in treating cerebral arteriovenous malformations (AVM's) and whether their purpose should be as a presurgical adjunct or as primary therapy. This controversy risks fragmentation between disciplines in the broader efforts to improve management of cerebrovascular disorders.
The authors report seven cases of life-threatening hemorrhages that occurred during staged invasive therapy for AVM's which illustrate the value of a unified team approach to optimize patient care. Each patient underwent at least one embolization procedure using polyvinyl alcohol particles, followed in two cases by the occlusion of proximal feeding vessels by platinum microcoils and in one case by the attempted detachment of an endovascular balloon. In three patients, catheter penetration into the subarachnoid space resulted in subarachnoid hemorrhage. One patient suffered rupture of a large feeding vessel during balloon inflation. The final three patients sustained intracranial hemorrhage 2 hours, 8 hours, and 5 days, respectively, following embolization. All but two patients underwent emergency craniotomy at the time of the complication. These cases underscore the advantages of interdisciplinary management optimizing decision-making and providing expeditious care when life-threatening complications develop.