Supraorbital and mini-pterional keyhole craniotomies for brain tumors

J Neurosurg 136:1314–1324, 2022

The authors’ objective was to compare the indications, outcomes, and anatomical limits of supraorbital (SO) and mini-pterional (MP) craniotomies in patients with intra- and extraaxial brain tumors, and to assess approach selection, utility of endoscopy, and surgical field overlap.

METHODS A retrospective analysis was conducted of all brain tumor patients who underwent an SO or MP approach. The analyzed characteristics included pathology, endoscopy use, extent of resection, length of stay (LOS), and complications. On the basis of preoperative MRI data, tumor heatmaps were constructed to compare surgical access provided by both routes, including coronal projection heatmaps for parasellar tumors.

RESULTS From 2007 to 2020, 158 patients underwent 173 (84.8%) SO craniotomies and 30 patients underwent 31 (15.2%) MP craniotomies; 71 (34.8%) procedures were reoperations. Of these 204 operations, 110 (63.6%) SO and 21 (67.7%) MP approaches were for extraaxial tumors (meningiomas in 65% and 76.2%, respectively). Gliomas and metastases together represented 84.1% and 70% of intraaxial tumors accessed with SO and MP approaches, respectively. Overall, 56.1% of tumors accessed with the SO approach and 41.9% of those accessed with the MP approach were in the parasellar region. Axial projection heatmaps showed that SO access extended along the entire ipsilateral and medial contralateral anterior cranial fossa, parasellar region, ipsilateral sylvian fissure, medial middle cranial fossa, and anterior midbrain, whereas MP access was limited to the ipsilateral middle cranial fossa, sylvian fissure, lateral parasellar region, and posterior aspect of anterior cranial fossa. Coronal projection heatmaps showed that parasellar access extended further superiorly with the SO approach compared with that of the MP approach. Endoscopy was utilized in 98 (56.6%) SO craniotomies and 7 (22.6%) MP craniotomies, with further tumor resection in 48 (49%) and 5 (71.4%) cases, respectively. Endoscope-assisted tumor removal was clustered in areas that were generally at farther distances from the craniotomy or in angled locations such as the cribriform plate region where microscopic visualization is limited. Gross-total or neartotal resection was achieved in 120/173 (69%) SO approaches and 21/31 (68%) MP approaches. Major complications occurred in 11 (6.4%) SO approaches and 1 (3.2%) MP approach (p = 0.49). The median LOS decreased to 2 days in the last 2 years of the study.

CONCLUSIONS This clinical experience suggests the SO and MP craniotomies are versatile, safe, and complementary approaches for tumors located in the anterior and middle cranial fossae and perisylvian and parasellar regions. The SO route, used in 85% of cases, achieved greater overall reach than the MP route. Both approaches may benefit from expanded visualization with endoscopy.

 

How I do it: minimizing muscle damage in microvascular decompression for hemifacial spasm

Acta Neurochirurgica (2021) 163:1045–1048

Key hole surgery was recruited for MVD surgery since the maneuver is through the small space between the cerebellum and temporal/occipital bone. However, even small wounds can cause severe postoperative pain if there is significant tissue damage. Attention has been given to the size of the craniotomy rather than to the skin incision or soft tissues such as muscles.

Method Suboccipital muscle dissection focusing on splitting the splenius capitis muscle was presented. The dura was reapproximated without additional dissection to harvest a fascia graft.

Conclusion Muscle injury should be minimized to alleviate postoperative pain.

Head-up display may facilitate safe keyhole surgery for cerebral aneurysm clipping

J Neurosurg 129:883–889, 2018

The head-up display (HUD) is a modern technology that projects images or numeric information directly into the observer’s sight line. Surgeons will no longer need to look away from the surgical view using the HUD system to confirm the preoperative or navigation image. The present study investigated the usefulness of the HUD system for performing cerebral aneurysm clipping surgeries.

METHODS Thirty-five patients underwent clipping surgery, including 20 keyhole surgeries for unruptured cerebral aneurysm, using the HUD system. Image information of structures such as the skull, cerebral vasculature, and aneurysm was integrated by the navigation software and linked with the positional coordinates of the microscope field of view. “Image injection” allowed visualization of the main structures that were concurrently tracked by the navigation image, and “closed shutter” switched the microscope field of view and the pointer image of the 3D brain image.

RESULTS The HUD system was effective for estimating the location and 3D anatomy of the aneurysm before craniotomy or dural opening in most patients. Scheduled keyhole minicraniotomy and opening of the sylvian fissure or partial rectal gyrus resection were performed on the optimized location with a minimum size in 20 patients.

CONCLUSIONS The HUD images superimposed on the microscope field of view were remarkably useful for less invasive and more safe aneurysm clipping and, in particular, keyhole clipping.