The Clinical Experience of Computed Tomographic-Guided Navigation System in C1-2 Spine Instrumentation Surgery

OBJECTIVE: To identify the accuracy and efficiency of the computed tomographic (CT)-based navigation system on upper cervical instrumentation, particularly C1 lateral mass and C2 pedicle screw fixation compared to previous reports. METHODS: Between May 2005 and March 2014, 25 patients underwent upper cervical instrumentation via a CT-based navigation system. Seven patients were excluded, while 18 patients were involved. There were 13 males and five females; resulting in four degenerative cervical diseases and 14 trauma cases. A CT-based navigation system and lateral fluoroscopy were used during the screw instrumentation procedure. Among the 58 screws inserted as C1-2 screws fixation, their precise positions were evaluated by postoperative CT scans and classified into three categories : in-pedicle, non-critical breach, and critical breach. RESULTS: Postoperatively, the precise positions of the C1-2 screws fixation were 81.1% (47/58), and 8.6% (5/58) were of non-critical breach, while 10.3% (6/58) were of critical breach. Most (5/6, 83.3%) of the critical breaches and all of non-critical breaches were observed in the C2 pedicle screws and there was only one case of a critical breach among the C1 lateral mass screws. There were three complications (two vertebral artery occlusions and a deep wound infection), but no postoperative instrument-related neurological deteriorations were seen, even in the critical breach cases. CONCLUSION: Although CT-based navigation systems can result in a more precise procedure, there are still some problems at the upper cervical spine levels, where the anatomy is highly variable. Even though there were no catastrophic complications, more experience are needed for safer procedure.

Minimally Invasive and Tailored Surgical Approach to the Anterior Circulation Aneurysms / 대한뇌혈관외과학회지

OBJECTIVES: Supraorbital route through eyebrow incision, mini-pterional craniotomy, and midline interhemispheric route are most generally used methods for key hole surgery on anterior circulation aneurysm. Surgical route is determined according to aneurysm architecture and patient status. The approaching route can be selected according to the findings of 3-dimensional computed tomography (CT) angiography simulation. Prospective decision-making protocol, surgical technique of key hole surgery, and the results are presented in this paper. METHODS: 173 patients with anterior circulation aneurysms were treated by direct surgical neck clipping during last two years. Twenty patients of poor grade (Hunt-Hess grade IV,V) were treated by craniectomy with clipping. Decision making protocol was applied to 153 unruptured and good grade ruptured aneurysm patients. Simulation of key hole surgery was conducted by CT work station using conventional software InSpace (Siemens, Germany), and direction and shape of aneurysm was observed from the perspective of microsurgery. RESULTS: 113 ruptured and 40 unruptured aneurysms were secured through one of the three approaching routes. Supraorbital approach had been performed in 82 cases (unruptured 24, ruptured 58) while 64 cases were treated by mini-pterional craniotomy. Midline key hole surgery were carried out in seven distal anterior circulation aneurysms (DACA) using brain navigation system. After locating the aneurysm, supraorbital approach was applied to 46 cases involving anterior cerebral artery (ACA), 16 in internal carotid artery (ICA) and 20 in middle cerebral artery (MCA). Mini-pterional craniotomy was carried out in aneurysms located in ACA (9), ICA (18), and MCA (37). In most cases, the results of clipping were good. The average follow-up time was 16.7months (ranging 2 to 32months) and the results were cosmetically excellent. CONCLUSION: Simulating surgical approaches with 3-D CT angiography is a highly useful method for determining various surgical routes in anterior circulation aneurysm treatment. Therefore, minimally invasive and tailored surgical approaches are recommended since optimal route can be found through simulation. Thus, minimal invasive and tailored surgical approach is available through this method. These procedures have clear advantages; shorter surgical time and hospital stay, less operative trauma, reduced costs and less pain, and better cosmetic outcomes compared to standard craniotomy. Optimal surgical results are expected from minimally invasive and tailored surgical craniotomy.

Clinical Experience with Double Cylindrical Cages for Anterior Cervical Interbody Fusion

OBJECTIVE: We performed the surgery using titanium double cylindrical cage for anterior cervical discectomy and interbody fusion in various degenerative cervical diseases. We compared the clinical results and radiologic results in cervical anterior disectomy. Method: From October 2007 to October 2008, 19 patients diagnosed with degenerative disease underwent anterior cervical disectomy and interbody fusion. The postsurgical clinical results were analyzed retrospectively by classifying them into four levels based on Odom's criteria(excellent, good, fair, and poor) after a more than 6-month follow-up period. RESULTS: In all cases, a single segment was involved, and surgery was performed for 19 segments. The C5-C6 inter-vertebral disc was the most commonly affected(9 cases). The clinical outcome was excellent, good, and fair in 5(26.3 %), 10(52.6%), and 4(21.0%) cases, respectively. An excellent or good outcome was considered as a successful result, showing an approximately 78.9% cure rate. No patient had aggravated symptoms compared with their preoperative status. CONCLUSION: Relatively satisfactory clinical and radiographic results were obtained with double cylindrical cages. The surgical method is relatively simple, allows good synostosis, and prevents many complications associated with autografting. It is also less traumatic to the spinal cord during cage insertion. Therefore, double cylindrical cages are generally more recommended for treating cervical spondylosis accompanied with flat cages.