Ruptured traumatic vertebral artery pseudoaneurysm in a child treated with trapping and posterior inferior cerebellar artery reimplantation

Microsurgical anatomical vascular study of the PICA-PICA bypass

OBJECTIVE

To assess the posterior inferior cerebellar artery (PICA)-PICA bypass possibility.

METHODS

Fifteen adult cadaver heads were used for surgical simulation, and the far-lateral approach was used to expose the surgical field. The bilateral PICA course, diameter, and perforators were observed and measured to evaluate the possibility of a PICA-PICA bypass.

RESULTS

The PICA-PICA bypass was performed in seven (46.7 %) of the 15 specimens; the procedure was performed easily in three specimens, a little difficult in two, and was difficult in two specimens because of the relationship between the tonsil and the short parallel length of the bilateral tonsillomedullary (p3) segment. In eight (53.3 %) of the 15 specimens, PICA-PICA bypass was not feasible for reasons including 1) the caliber of the bilateral p3 was unmatched for bypass, 2) the distance of bilateral p3 in the midline was > 7 mm, 3) the middle segment of p3 perforating direct arteries limited the buffer length, and 4) single caudal loops.

CONCLUSION

The possibility of PICA-PICA bypass was determined by the proximity of the bilateral p3, caliber match, and mobilization of the bilateral caudal loop due to the perforators. The difficulty of the PICA-PICA bypass mainly depends on the relationship between the cerebellar tonsil and the parallel length of the bilateral PICA in the midline.

Occult posterior inferior cerebellar artery dissection requiring endovascular treatment following pediatric head trauma: case report

This is the eighth case report of a pediatric dissecting posterior inferior cerebellar artery aneurysm. The authors present the case of a 13-year-old boy who presented with posttraumatic posterior fossa subdural, subarachnoid, and intraventricular hemorrhage with hydrocephalus. Initial vascular imaging findings were negative; however, a high level of suspicion is necessary. The aneurysm was identified on day 20, after recurrence of hydrocephalus, and was treated with endovascular vessel sacrifice. The patient made a good recovery. It is important to consider arterial dissection in pediatric traumatic brain injury, especially with suspicious findings on initial CT scan and clinical presentation out of proportion to the mechanism of injury. Delayed vascular imaging is imperative for appropriate management.

Complications, outcomes, and management strategies of non-missile penetrating head injuries

OBJECTIVE

While high-velocity missile injury (gunshot) is associated with kinetic and thermal injuries, non-missile penetrating head injury (NMPHI) results in primary damage along the tract of the piercing object that can be associated with significant secondary complications. Despite the unique physical properties of NMPHI, factors associated with complications, expected outcomes, and optimal management have not been defined. In this study, the authors attempted to define those factors.

METHODS

Consecutive adult patients with NMPHI who presented to Tygerberg Academic Hospital (Cape Town, South Africa) in the period from August 1, 2011, through July 31, 2018, were enrolled in a prospective study using a defined treatment algorithm. Clinical, imaging, and laboratory data were analyzed.

RESULTS

One hundred ninety-two patients (185 males [96%], 7 females [4%]) with 192 NMPHIs were included in this analysis. The mean age at injury was 26.2 ± 1.1 years (range 18-58 years). Thirty-four patients (18%) presented with the weapon in situ. Seventy-one patients (37%) presented with a Glasgow Coma Scale (GCS) score of 15. Weapons included a knife (156 patients [81%]), screwdriver (18 [9%]), nail gun (1 [0.5%]), garden fork (1 [0.5%]), barbeque fork (1 [0.5%]), and unknown (15 [8%]). The most common wound locations were temporal (74 [39%]), frontal (65 [34%]), and parietal (30 [16%]). The most common secondary complications were vascular injury (37 patients [19%]) and infection (27 patients [14%]). Vascular injury was significantly associated with imaging evidence of deep subarachnoid hemorrhage and an injury tract crossing vascular territory (p ≤ 0.05). Infection was associated with delayed referral (> 24 hours), lack of prophylactic antibiotic administration, and weapon in situ (p ≤ 0.05). A poorer outcome was associated with a stab depth > 50 mm, a weapon removed by the assailant, vascular injury, and eloquent brain involvement (p ≤ 0.05). Nineteen patients (10%) died from their injuries. The Glasgow Outcome Scale (GOS) score was linearly related to the admission GCS score (p < 0.001). One hundred forty patients (73%) had a GOS score of 4 or better at discharge.

CONCLUSIONS

The most common NMPHI secondary complications are vascular injury and infection, which are associated with specific NMPHI imaging and clinical features. Identifying these features and using a systematic management paradigm can effectively treat the primary injury, as well as diagnose and manage NMPHI-related complications, leading to a good outcome in the majority of patients.

Posterior inferior cerebellar artery reimplantation: buffer lengths, perforator anatomy, and technical limitations

OBJECTIVE

Reimplantation of the posterior inferior cerebellar artery (PICA) to the vertebral artery (VA) is a safe and effective bypass option after deliberate PICA sacrifice during the treatment of nonsaccular and dissecting aneurysms at this location. However, the anatomy and limitations of this technique have not been studied. The goal of this study was to define the surgical anatomy and buffer lengths specific to the proximal segment of the PICA related to 2 variations of PICA reimplantation: 1) reimplantation “along-VA” (simulating a dissecting VA aneurysm), and 2) reimplantation “across-VA” (simulating a nonclippable, proximal PICA aneurysm).

METHODS

Ten cadaver heads (20 sides) were prepared for surgical simulation. Twenty far-lateral approaches were performed. The PICA was mobilized and reimplanted onto the VA according to 2 different paradigms: 1) transposition along the axis of the VA (along-VA) to simulate a dissecting VA, and 2) transposition perpendicular to the axis of the VA (across-VA) to simulate a nonclippable, proximal PICA aneurysm. The buffer lengths provided by mobilization of the artery in each paradigm were measured and the anatomy of perforator branching on the proximal PICAs was analyzed.

RESULTS

The PICA was reimplanted in all surgical simulations. The most common perforating artery on the P1 and P2 segments was the short circumflex type. No direct perforator was found on the P1 segment. The mean buffer length with reimplantation along the VA axis was 13.43 ± 4.61 mm, and it was 6.97 ± 4.04 mm with reimplantation across the VA. The PICA was less maneuverable when it was reimplanted across the VA, due to perforator branches of the PICA (P3 segment).

CONCLUSIONS

The buffer lengths measured in this study describe the limitations of PICA reimplantation as a revascularization procedure for nonsaccular aneurysms in this location. PICA reimplantation is a revascularization option for dissecting VA aneurysms incorporating the PICA origin that are < 13 mm in length, and for nonsaccular proximal PICA aneurysms that are < 6 mm in diameter. The final decision to reimplant the PICA depends on careful inspection of perforator anatomy that is not visible preoperatively on angiography, as well as an assessment of technical difficulty intraoperatively.

Subarachnoid haemorrhage secondary to traumatic intracranial aneurysm of the posterior cerebral circulation: case series and literature review

Background

To identify the clinical features, rebleed risk, timing and method of diagnosis, complications and outcome for subarachnoid haemorrhage (SAH) from traumatic intracranial aneurysm (TICA) of the posterior circulation. Subjects included 26 patients aged 3–54 (mean 24.8).

Methods

Case series and literature search to identify all reported cases.

Results

In our series, two of three cases were fatal as a result of rebleed, and one case had a good outcome with no deficit, following prompt diagnosis and embolisation. Our key findings from the literature review were: 30.7 % of patients were age 16 and under; 88 % had an acute drop in consciousness, 46 % in a delayed manner; the mean time to diagnosis was 7.5 days; initial cerebrovascular imaging was normal in 23 %; the rebleed rate was 23 %; 61 % required emergency diversion of cerebrospinal fluid; 11 % developed vasospasm requiring treatment; 19.2 % had deficits that rendered them unable to live independently. The mortality rate was 27 %.

Conclusions

SAH from ruptured posterior circulation TICA is associated with significant morbidity and mortality. A high index of suspicion as well as prompt diagnosis, repeat imaging in selected cases, and treatment of any associated TICA can be crucial to a favourable outcome.

Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients

OBJECT 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Pediatric bypasses for aneurysms and skull base tumors: short- and long-term outcomes

OBJECT

Cerebral bypass is a useful microsurgical technique for the treatment of unclippable aneurysms and invasive skull base tumors. The authors present the largest reported series of cerebrovascular bypasses in the pediatric population. They describe the short- and long-term clinical and radiographic outcomes of extracranial-intracranial and local bypasses performed for complex cerebral aneurysms and recurrent, invasive, and malignant skull base tumors in pediatric patients.

METHODS

A consecutive series of 17 pediatric patients who underwent revascularization were analyzed retrospectively for indications, graft patency, and neurological outcomes.

RESULTS

The mean age was 12 years (median 11 years, range 4-17 years), and there were 7 boys (41%) and 10 girls (59%). A total of 18 bypasses were performed in 17 patients and included 10 aneurysm cases (55.5%) and 8 tumor cases (45%). Of these 18 bypasses, there were 11 (61.1%) extracranial-intracranial bypasses (10 saphenous vein grafts [90%] and 1 radial artery graft [10%]), 1 side-to-side anastomosis (5.5%), 2 intracranial reimplants (11.1%), and 4 interposition bypass grafts (22.2%; 2 radial artery grafts, 1 saphenous vein graft, and 1 lingual artery graft). The mean clinical follow-up was 40.5 months (median 24 months, range 3-197 months). The mean radiographic follow-up was 40 months (median 15 months, range 9-197 months). Eighty-two percent of patients (14 of 17) achieved a modified Rankin Scale score between 0 and 2; however, 2 patients died of disease progression during long-term follow-up. The short-term (0- to 3-month) graft patency rate was 100%. Two patients had graft stenosis (11.7%) and underwent graft revisions. Two patients (11.1%) with giant middle cerebral artery aneurysms (> 25 mm) had strokes postoperatively but recovered without a persistent neurological deficit. One patient observed for 197 months showed a stable dysplastic change at the end of the graft. The long-term graft patency was 100% with a mean follow-up of 40 months. There were 2 deaths in the cohort during follow-up; both patients died of malignant tumors (osteogenic sarcoma and chondrosarcoma).

CONCLUSIONS

The authors conclude that in properly selected cases, bypasses can be safely performed in patients with aneurysms and skull base tumors. The bypasses remained patent over long periods of time despite the growth of the patients.

Acute formation of a pseudoaneurysm adjacent to a previously clipped anterior communicating artery aneurysm

Background:

Cerebral pseudoaneurysms, especially of the anterior communicating artery (ACoA), are rare.

Case Description:

Herein, the authors report a 66-year-old patient who underwent successful clip ligation of a small ruptured ACoA aneurysm. Eighteen days after surgery, he suffered from another episode of subarachnoid hemorrhage due to the rupture of a newly formed pseudoaneurysm adjacent to the previously clipped aneurysm. This pseudoaneurysm was treated through clip ligation as well.

Conclusion:

A pseudoaneurysm may rarely form adjacent to a previously clipped cerebral aneurysm and should be included in the differential diagnosis of recurrent subarachnoid hemorrhage. Potential mechanisms of formation and management strategies for this challenging problem will be discussed.

Endovascular treatment and radiographic follow-up of proximal traumatic intracranial aneurysms in adolescents: case series and review of the literature

PURPOSE

Traumatic intracranial aneurysms are rare lesions that are relatively more common in the pediatric population. Proximal traumatic aneurysms occur near the skull base. Direct surgical repair of these lesions is difficult due to the anatomically confined area, clinical status of a head injury patient, and the transmural nature of the injury. These lesions often lack a definable neck or wall suitable for clipping. While the indications and capabilities of endovascular treatment continue to expand, there are unanswered questions about the durability of treatment, especially in young patients. There are few reports examining the radiographic outcomes of endovascular treatment specifically for traumatic intracranial aneurysms. Therefore, we examined our experience treating these rare proximal lesions in an adolescent population.

METHODS

A retrospective review of prospectively collected data from 2000-2008 in a large, multidisciplinary neurovascular and trauma center was performed.

RESULTS

Three pediatric patients received endovascular treatment for traumatic intracranial aneurysms near the skull base. All patients had successful obliteration of their lesion without vessel sacrifice; however, two patients required multiple procedures for coil compaction or refilling of the aneurysm. There were no complications or ischemic events related to treatment. Follow-up imaging ranged from 6 months to 3.5 years.

CONCLUSIONS

Traumatic intracranial aneurysms at the skull base can be successfully treated with endovascular methods; however, close follow-up is necessary.