Adib A. Abla and Michael T. Lawton
Adib A. Abla and Michael T. Lawton
The authors describe their experience with intracranial-to-intracranial (IC-IC) bypasses for complex anterior cerebral artery (ACA) aneurysms with giant size, dolichoectatic morphology, or intraluminal thrombus; they determine how others have addressed the limitations of ACA bypass; and they discuss clinical indications and microsurgical technique.
A consecutive, single-surgeon experience with ACA aneurysms and bypasses over a 16-year period was retrospectively reviewed. Bypasses for ACA aneurysms reported in the literature were also reviewed.
Ten patients had aneurysms that were treated with ACA bypass as part of their surgical intervention. Four patients presented with subarachnoid hemorrhage and 3 patients with mass effect symptoms from giant aneurysms; 1 patient with bacterial endocarditis had a mycotic aneurysm, and 1 patient's meningioma resection was complicated by an iatrogenic pseudoaneurysm. One patient had his aneurysm discovered incidentally. There were 2 precommunicating aneurysms (A1 segment of the ACA), 5 communicating aneurysms (ACoA), and 3 postcommunicating (A2–A3 segments of the ACA). In situ bypasses were used in 4 patients (A3-A3 bypass), interposition bypasses in 4 patients, reimplantation in 1 patient (pericallosal artery-to-callosomarginal artery), and reanastomosis in 1 patient (pericallosal artery). Complete aneurysm obliteration was demonstrated in 8 patients, and bypass patency was demonstrated in 8 patients. One bypass thrombosed, but 4 years later. There were no operative deaths, and permanent neurological morbidity was observed in 2 patients. At last follow-up, 8 patients (80%) were improved or unchanged. In a review of the 29 relevant reports, the A3-A3 in situ bypass was used most commonly, extracranial (EC)–IC interpositional bypasses were the second most common, and reanastomosis and reimplantation were used the least.
Anterior cerebral artery aneurysms requiring bypass are rare and can be revascularized in a variety of ways. Anterior cerebral artery aneurysms, more than any other aneurysms, require a thorough survey of patient-specific anatomy and microsurgical options before deciding on an individualized management strategy. The authors' experience demonstrates a preference for IC-IC reconstruction, but EC-IC bypasses are reported frequently in the literature. The authors conclude that ACA bypass with indirect aneurysm occlusion is a good alternative to direct clip reconstruction for complex ACA aneurysms.
Adib A. Abla, Cameron M. McDougall, Jonathan D. Breshears and Michael T. Lawton
Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed.
Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA’s origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included.
During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients.
PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.
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.
Adib Adnan Abla, Aaron J. Clark and Michael T. Lawton
In this video, we illustrate a right far-lateral craniotomy for resection of a 13-mm cavernous malformation of the pons in a healthy 53-year-old female patient presenting with diplopia and right 6th nerve palsy. The cavernous malformation was surrounded by normal pons, but was within 1 mm of the pontomedullary sulcus. The lesion was exposed from below through a far lateral craniotomy and accessed through the vasoaccessory triangle, superior to olivary nucleus and 12th cranial nerve. The alternative retrosigmoid craniotomy would have involved significant transgression of the middle cerebellar peduncle. The patient had gross-total resection and some temporary increase in her abducens nerve palsy without any complication.
The video can be found here: http://youtu.be/f14RR3CHQkw.
Adib Adnan Abla, Dario J. Englot and Michael T. Lawton
In this operative video, we demonstrate the approach to a 10-mm distal left vertebral artery and proximal basilar artery blister aneurysm in a 62-year-old male presenting with subarachnoid hemorrhage. He initially underwent clipping of the ruptured ACoA aneurysm and two incidental right MCA aneurysms. Ten days later, the posterior circulation aneurysms were clipped through an extended retrosigmoid approach, working between cranial nerves 9–11 inferiorly and 7–8 superiorly. The vertebral artery was accessible from its dural entry site to the vertebrobasilar junction with the rostral limit of the exposure at the level of the tentorium. He underwent uneventful clipping of all aneurysms without postoperative morbidity.
The video can be found here: http://youtu.be/O0lF0gkFZxc.
Scott D. Wait, Adib A. Abla, Brendan D. Killory, Peter Nakaji and Harold L. Rekate
Hypothalamic hamartomas (HHs) are devastating lesions causing refractory epilepsy, rage attacks, social ineptitude, and precocious puberty. Microsurgical and/or endoscopic resection offers an excellent risk/benefit profile for cure or improvement of epilepsy.
The authors reviewed a prospective database maintained during the first 7 years of the Barrow Hypothalamic Hamartoma program. They describe and illustrate their surgical methods, and they review data from several previous publications regarding surgical outcome.
To date, the authors have performed surgery in 165 patients for symptomatic HHs. Patients underwent an endoscopic, transcallosal, or skull base approach, or multiple approaches. Twenty-six patients (15.8%) required more than 1 treatment for their HH.
Microsurgical and endoscopic resection of symptomatic HHs are technically demanding but can be performed safely with excellent results and an acceptable risk profile. Meticulous attention to the subtleties of surgical management helps optimize outcomes.
Timothy Uschold, Adib A. Abla, David Fusco, Ruth E. Bristol and Peter Nakaji
The heterogeneous clinical manifestations and operative characteristics of pathological entities in the pineal region represent a significant challenge in terms of patient selection and surgical approach. Traditional surgical options have included endoscopic transventricular resection; open supratentorial microsurgical approaches through the midline, choroidal fissure, lateral ventricle, and tentorium; and supracerebellar infratentorial (SCIT) approaches through the posterior fossa. The object of the current study was to review the preoperative characteristics and outcomes for a cohort of patients treated purely via the novel endoscopically controlled SCIT approach.
A single-institution series of 9 consecutive patients (4 male and 5 female patients [10 total cases]; mean age 21 years, range 6–37 years) treated via the endoscopically controlled SCIT approach for a pathological entity in the pineal region was retrospectively reviewed. The mean follow-up time was 13.2 months.
The endoscopically controlled SCIT approach was successfully used to approach a variety of pineal lesions, including pineal cysts (6 patients), epidermoid tumor, WHO Grade II astrocytoma (initial biopsy and recurrence), and malignant mixed germ cell tumor (1 patient each). Gross-total resection and/or adequate cyst fenestration was achieved in 8 cases. Biopsy with conservative debulking was performed for the single case of low-grade astrocytoma and again at the time of recurrence.
The mean preoperative tumor and cyst volumes were 9.9 ± 4.4 and 3.7 ± 3.2 cm3, respectively. The mean operating times were 212 ± 71 minutes for tumor cases and 177 ± 72 minutes for cysts. Estimated blood loss was less than 150 ml for all cases. A single case (pineal cyst) was converted to an open microsurgical approach to enhance visualization. There were no operative complications, as well as no documented CSF leaks, additional CSF diversion procedures, or air emboli. Seven patients underwent concomitant third ventriculostomy into the quadrigeminal cistern. At the time of the last follow-up evaluation, all patients had a stable or improved modified Rankin Scale score.
The endoscopically controlled SCIT approach may be used for the biopsy and resection of appropriately selected solid tumors of the pineal region, in addition to the fenestration and/or resection of pineal cysts. Preoperative considerations include patient presentation, anticipated disease and vascularity, degree of local venous anatomical distortion, and selection of optimal paramedian trajectory.
Richard W. Williamson, David A. Wilson, Adib A. Abla, Cameron G. McDougall, Peter Nakaji, Felipe C. Albuquerque and Robert F. Spetzler
Subarachnoid hemorrhage (SAH) from ruptured posterior inferior cerebellar artery (PICA) aneurysms is uncommon, and long-term outcome data for patients who have suffered such hemorrhages is lacking. This study investigated in-hospital and long-term clinical data from a prospective cohort of patients with SAH from ruptured PICA aneurysms enrolled in a randomized trial; their outcomes were compared with those of SAH patients who were treated for other types of ruptured intracranial aneurysms. The authors hypothesize that PICA patients fare worse than those with aneurysms in other locations and this difference is related to the high rate of lower cranial nerve dysfunction in PICA patients.
The authors analyzed data for 472 patients enrolled in the Barrow Ruptured Aneurysm Trial (BRAT) and retrospectively reviewed vasospasm data not collected prospectively. In the initial cohort, 57 patients were considered angiographically negative for aneurysmal SAH source and did not receive treatment for aneurysms, leaving 415 patients with aneurysmal SAH.
Of 415 patients with aneurysmal SAH, 22 (5.3%) harbored a ruptured PICA aneurysm. Eight of them had dissecting/fusiform-type aneurysms while 14 had saccular-type aneurysms. Nineteen PICA patients were treated with clipping (1 crossover from coiling), 2 were treated with coiling, and 1 died before treatment. When comparing PICA patients to all other aneurysm patients in the study cohort, there were no statistically significant differences in age (mean 57.6 ± 11.8 vs 53.9 ± 11.8 years, p = 0.17), Hunt and Hess grade median III [IQR II–IV] vs III [IQR II–III], p = 0.15), Fisher grade median 3 [IQR 3–3] vs 3 [IQR 3–3], p = 0.53), aneurysm size (mean 6.2 ± 3.0 vs 6.7 ± 4.0 mm, p = 0.55), radiographic vasospasm (53% vs 50%, p = 0.88), or clinical vasospasm (12% vs 23%, p = 0.38). PICA patients were more likely to have a fusiform aneurysm (36% vs 12%, p = 0.004) and had a higher incidence of lower cranial nerve dysfunction and higher rate of tracheostomy/percutaneous endoscopic gastrostomy placement compared with non-PICA patients (50% vs 16%, p < 0.001). PICA patients had a significantly higher incidence of poor outcome at discharge (91% vs 67%, p = 0.017), 1-year follow-up (63% vs 29%, p = 0.002), and 3-year follow-up (63% vs 32%, p = 0.006).
Patients with ruptured PICA aneurysms had a similar rate of radiographic vasospasm, equivalent admission Fisher grade and Hunt and Hess scores, but poorer clinical outcomes at discharge and at 1- and 3-year follow-up when compared with the rest of the BRAT SAH patients with ruptured aneurysms. The PICA's location at the medulla and the resultant high rate of lower cranial nerve dysfunction may play a role in the poor outcome for these patients. Furthermore, PICA aneurysms were more likely to be fusiform than saccular, compared with non-PICA aneurysms; the complex nature of these aneurysms may also contribute to their poorer outcome.
Sandipan Pati, Adib A. Abla, Harold L. Rekate and Yu-Tze Ng
Hypothalamic hamartomas (HHs) often cause pharmacoresistent epilepsy, incapacitating behavioral abnormalities, and cognitive decline. Surgical intervention offers the patient the best opportunity of seizure resolution, which occurs in approximately 50%–60% of patients, and improvement in both cognitive and behavioral difficulties. For those in whom the initial operation has failed, further medical treatment options remain quite limited, whereas, in some cases, a second surgery may improve seizure outcome. The authors retrospectively reviewed their surgical cases to document the success rate and complications of reoperations in patients with HHs.
Data were obtained from the HH epilepsy surgery database at the Barrow Neurological Institute between 2003 and 2010. Surgical treatment consisted of open and endoscopic procedures, as well as radiosurgery. Demographic details, seizure history, presurgical evaluation, and postoperative follow-up data were evaluated.
In the last 7 years, 21 (13%) of 157 patients underwent reoperation after an initial epilepsy operation. The initial surgical approach in the 21 patients included: endoscopic (8 patients [38%]), transcallosal (8 patients [38%]), orbitozygomatic (3 patients [14%]), and radiosurgery (2 patients [10%]). Of the 8 patients who initially underwent endoscopic resection, repeat procedures included: radiosurgery in 4 (50%), an orbitozygomatic approach in 2 (25%), repeat endoscopy in 1 (12.5%), and a transcallosal approach in 1 (12.5%). Repeat procedures after an initial transcallosal resection included: endoscopic resection in 2 (25%); radiosurgery in 1 (12%); an orbitozygomatic approach in 2 (25%), and repeat transcallosal surgery in 3 (38%). Predominant seizure types that recurred after the first surgery were gelastic seizures, complex partial seizures, and tonic-clonic seizures. Magnetic resonance imaging in all patients prior to reoperation demonstrated either residual HH and/or connection with the mammillary bodies. Review of patients with more than 6 months of follow-up since the last surgery showed greater than 90% reduction in seizures in 4 patients (19%) and by 50%–90% in 10 patients (48%). Two patients were seizure free, and in 5 patients (24%) there was no change in seizure frequency. Following reoperation, none of the patients had any worsened behavioral issues such as increased rage attacks or disruptive violent behavior. New postoperative complications after reoperation included hemiparesis, thalamic stroke (asymptomatic and symptomatic), hyperphagia, and panhypopituitarism.
Reoperation should be considered in selected patients with HH in whom initial epilepsy surgery fails because more than half the patients have significant reductions in seizure.