Joshua T. Wewel

Frameless neuronavigation based only on 3D digital subtraction angiography using surface-based facial registration

OBJECT Cerebrovascular lesions can have complicated abnormal anatomy that is not completely characterized by CT or MR angiography. Although 3D rotational angiography provides superior spatial and temporal resolution, catheter angiograms are not easily registered to the patient, limiting the use of these images as a source for neuronavigation. However, 3D digital subtraction angiography (DSA) contains not only vascular anatomy but also facial surface anatomy data. The authors report a novel technique to register 3D DSA images by using only the surface anatomy contained within the data set without having to fuse the DSA image set to other imaging modalities or use fiducial markers. METHODS A cadaver model was first created to assess the accuracy of neuronavigation based on 3D DSA images registered by facial surface anatomy. A 3D DSA scan was obtained of a formalin-fixed cadaver head, with acquisitions of mask and contrast runs. The right common carotid artery was injected prior to the contrast run with a 45% contrast solution diluted with water-soluble red liquid latex. One week later, the head was registered to a neuronavigation system loaded with the 3D DSA images acquired earlier using facial surface anatomy. A right pterional craniotomy was performed and 10 different vascular landmarks were identified and measured for accuracy using the neuronavigation system. Neuronavigation based only on 3D DSA was then used to guide an open clipping procedure for a patient who presented with a ruptured distal lenticulostriate aneurysm. RESULTS The accuracy of the measurements for the cadaver model was 0.71 ± 0.25 mm (mean ± SE), which is superior to the 1.8-5 mm reported for neuronavigation. The 3D DSA-based navigation-assisted surgery for the distal lenticulostriate aneurysm aided in localization, resulting in a small craniotomy and minimal brain dissection. CONCLUSIONS This is the first example of frameless neuronavigation based on 3D catheter angiography registered by only the surface anatomy data contained within the 3D DSA image set. This is an easily applied technique that is beneficial for accurately locating vascular pathological entities and reducing the dissection burden of vascular lesions.

Perioperative Cost Analysis of Minimally Invasive vs Open Resection of Intradural Extramedullary Spinal Cord Tumors

BACKGROUND Minimally invasive spinal surgery (MIS) has emerged as a clinically effective tool but its cost-effectiveness remains unclear. No studies have compared MIS vs open surgical techniques for the treatment of intradural extramedullary (IDEM) tumors. OBJECTIVE To analyze and compare open and MIS techniques for resection of IDEM tumors, with focus on perioperative costs. METHODS Retrospective analysis of a prospectively collected database including 35 IDEM patients (18 open, 17 MIS). Perioperative data, hospital costs, and hospital and physician charges for in-hospital services associated with the index surgical procedure and readmissions within 90 days were compared. RESULTS Mean estimated blood loss, operative time, preoperative hospital charges, and physician fees were similar between open and MIS techniques. Patient and tumor characteristics were similar between groups. MIS cases were associated with shorter intensive care unit and floor stay. There were 3 complications in the open group, requiring 2 readmissions and 1 reoperation. Hospital costs (

Minimally invasive surgery for synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation

21 307.80 open,

Iatrogenic traumatic intracranial aneurysm after endoscopic sinus surgery

15 015.20 MIS, P < .01), and postoperative (

Novel reconstruction of the anterior craniocervical junction using an expandable cage with integrated fixation after total C2 spondylectomy for chordoma

75 383.48 open,

Deep brain stimulation with a pre-existing cochlear implant: Surgical technique and outcome

56 006.88 MIS, P < .01) and total charges (

Idiopathic thoracic transdural intravertebral spinal cord herniation

100 779.38 open,

Delayed Intracerebral Hemorrhage from a Pseudoaneurysm Following a Depressed Skull Fracture.

76 100.92 MIS, P < .01) were significantly lower in the MIS group. There were no tumor recurrences in either group. All patients except for one in the open group maintained or improved their Nurick score. CONCLUSION Both MIS and open techniques were able to adequately treat IDEM tumors. Reductions in complication rate and intensive care unit and hospital stay led to a decrease in hospital costs of almost 30% in the MIS group. MIS resection of IDEM tumors is not only an effective and safe option, but allows faster hospital discharge and significant cost savings.

Post-transplant lymphoproliferative disorder of the cervical spine mimicking an epidural abscess

Schwannomas are the most common intradural-extramedullary spinal tumors, with an estimated incidence of 3 to 10 cases per 100,000 people. With continued advances in minimally invasive surgery (MIS) over recent years, MIS techniques have been utilized by spine surgeons in the resection of intradural spinal neoplasms with favorable surgical results and clinical outcomes. This video demonstrates a rare case of symptomatic, synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation, both of which were successfully treated using a single MIS approach. Surgical pearls and nuances are discussed to better delineate technique and minimize potential complications. The video can be found here: http://youtu.be/78ibbicBRUk.

Spinal aneurysmal bone cyst presenting as acute paraparesis during pregnancy.

Iatrogenic traumatic intracranial aneurysms are rare, but their clinical impact is significant secondary to their risk of intracranial hemorrhage and in their frequent complexity in management. We report an adult patient with a history of chronic sinusitis who, while undergoing elective endoscopic polypectomy, suffered an iatrogenic injury to an A2 segment branch of the left anterior cerebral artery, resulting in a pseudoaneurysm. Management included endovascular coiling and a bicoronal craniotomy approach, using a split-thickness cranial graft and abdominal fat graft to repair the associated left cribriform plate defect.