Thomas M. Wascher, Robert F. Spetzler and Joseph M. Zabramski
✓ Safe surgery for vascular and neoplastic lesions involving the cavernous sinus requires adequate proximal control of the cavernous internal carotid artery (ICA). Classically, control of the cavernous ICA has necessitated dissection and isolation of the cervical vessels. The authors describe an alternative method for obtaining vascular control via transdural exposure of the petrous ICA and the use of the Fogarty balloon embolectomy catheter inserted extra-arterially into the carotid canal to provide temporary occlusion. This method is particularly well suited for proximal ICA occlusion during short-segment petrous-to-paraclinoid ICA bypass procedures as it eliminates the need for a temporary proximal ICA aneurysm clip and increases the available working space for completion of the anastomosis.
M. Yashar S. Kalani and Joseph M. Zabramski
The threat of symptomatic hemorrhage from cerebral cavernous malformations (CCMs) during pregnancy remains poorly understood. The authors undertook this study to better define the risk of pregnancy-related hemorrhage in this population.
The records of female patients with sporadic (isolated lesions and negative family history) and familial forms of CCM, which were collected as part of the Barrow Neurological Institute CCM natural history study, were examined. Clinical data related to pregnancy, including type of delivery (vaginal or cesarean section) and any change in neurological status, were obtained from chart reviews and patient interviews.
There were 168 pregnancies among 64 female patients with CCM (28 sporadic and 36 familial). Assuming an average of 46 weeks per pregnancy (40 weeks of gestation and 6 weeks of puerperium), patients were at risk for hemorrhage for a total of 148.6 years. Symptomatic hemorrhage (defined as new-onset or exacerbation of seizure activity or any change in neurological status) occurred during 5 pregnancies, with the most common symptom being seizures (4 cases). The overall risk for symptomatic hemorrhage was 3% per pregnancy; the risk was 1.8% per pregnancy in the sporadic group and 3.6% per pregnancy in the familial patients.
There were 19 deliveries by cesarean section: 5 for obstetrical reasons, 8 for fear of possible hemorrhage, and 6 for unknown reasons. Vaginal delivery was performed without complications for the remaining 149 pregnancies.
The authors' experience suggests that the risk of symptomatic hemorrhage from a CCM during pregnancy is not increased and that a history of CCM is not a contraindication to pregnancy or vaginal delivery.
Robert F. Spetzler, Joseph M. Zabramski and Richard A. Flom
✓ A small group of spinal arteriovenous malformations (AVM's), most commonly present in children or young adults, are characterized by a large size, high flow, the presence of multiple feeders, and frequent extension to paraspinous structures. Cardiac output requirements may be significantly increased by these so-called “juvenile” malformations, and a bruit is commonly noted. This report describes the obliteration of a juvenile spinal AVM. Staging of embolization and operative procedures was used to obliterate the AVM successfully without morbidity.
Joshua B. Bederson, Joseph M. Zabramski and Robert F. Spetzler
✓ The authors describe a new technique for treating unclippable aneurysms. The method involves a modification of the traditional wrapping technique, including a clip-reinforced cotton sling. The results of this method in four patients are presented.
Carlos A. David, Joseph M. Zabramski and Robert F. Spetzler
✓ The authors sought to create a saphenous vein interposition graft to be used in cerebral bypass procedures that would be more physiologically appropriate than standard vein grafts and would provide a better match between the graft and recipient vessels at the anastomotic sites. The saphenous vein graft was prepared by lysing the valves with a valvulotome. The blood flow could then be reversed in the vein, allowing it to be used in either direction as a bypass graft. An illustrative case including angiograms that confirm good patency and blood flow through the reversed-flow bypass graft is presented. It is concluded that the reversed-flow saphenous vein graft provides a more physiologically suitable conduit than standard vein grafts. Lysis of the valves allows the graft to be used in an orientation that takes advantage of the natural tapering of the vein to produce a better match with the recipient vessels at the anastomotic sites. Minimizing diameter changes at the proximal and distal anastomoses helps reduce turbulence, which has been implicated as a cause of early graft failure and thrombosis.
Andrew G. Shetter, Joseph M. Zabramski and Burton L. Speiser
Object. The authors sought to determine whether the results of trigeminal microvascular decompression (MVD) are influenced by prior gamma knife surgery (GKS).
Methods. Gamma knife surgery is an established procedure for treating medically intractable trigeminal neuralgia but failures do occur. The authors assessed six patients (two men and four women; mean age 52 years) who experienced pain recurrence after GKS and elected to undergo trigeminal MVD via retrosigmoid craniotomy. Three patients underwent a single GKS to a maximal dose of 80 Gy, whereas three others underwent a second GKS to total of 120 to 135 Gy.
At surgery, none of the six patients demonstrated excess arachnoid thickening, grossly apparent changes in the nerve itself, or any other tissue alterations that made successful mobilization of a blood vessel from the trigeminal root entry zone technically more difficult. A single individual had a small atherosclerotic plaque in the superior cerebellar artery near its contact point with the trigeminal nerve. Follow up at a mean of 25.4 months (range 7.5–42 months) indicated that five patients were pain free. One patient had improved but still relied on medications for pain control.
Conclusions. In the authors' experience, trigeminal MVD can be performed without added difficulty in patients who have previously undergone GKS. The success rates seem similar to those normally associated with MVD. Patients who elect the less invasive option of GKS can be assured that trigeminal MVD remains a viable alternative at a later date if further surgery is required.
Robert F. Spetzler, Felipe C. Albuquerque, Joseph M. Zabramski and Peter Nakaji
Adib A. Abla, Timothy Uschold, Mark C. Preul and Joseph M. Zabramski
The aim of this study was to describe a turkey wing model for microvascular anastomosis training and compare it to the previously outlined chicken wing model.
The authors compared diameter measurements in each of 5 turkey and 5 chicken brachial arteries at 3 equidistant points. Usable vessel length was measured (from joint to joint) in each of the specimens. A survey was created and distributed at a bypass training course to assess the attendees' impressions of various practice models used for bypass.
The turkey wing brachial artery was consistently larger in diameter (p < 0.01) and longer (p < 0.01) than the chicken wing artery and showed less variability in the vessel diameter (1.47 ± 0.14 mm in the turkey vs 1.07 ± 0.25 mm in the chicken). In a survey of 15 bypass course participants, the live rat training model scored highest overall and was ranked as the best model for training; however, the turkey wing model was ranked second best and was consistently scored ahead of the chicken wing and silastic tube training models.
The authors' institutional preference has shifted to the use of a turkey wing artery as the initial model for microanastomosis training. Advantages in terms of vessel size and tissue durability favor this model over the chicken wing as part of a graduated instruction process.
Robert F. Spetzler, Takanori Fukushima, Neil Martin and Joseph M. Zabramski
✓ In the management of cavernous sinus aneurysms, cavernous sinus tumor, and cavernous internal carotid artery (ICA) stenosis, a direct arterial bypass around the pathology may be required. A series of 18 patients is presented in whom a petrous ICA to subarachnoid ICA saphenous vein bypass procedure was performed. The advantages of a short large-caliber venous graft entirely within the skull account for the high patency rate (17 of 18 patients) in this series. This vascular bypass can be recommended in the management of patients whose intracavernous ICA must be sacrificed.