A Comparison of Decompression Size and Craniectomy Speed of Reverse Question Mark Versus Retroauricular Incisions for Decompressive Hemicraniectomy: A Cadaver Study

Background and objectives: Decompressive hemicraniectomy is a common emergent surgery for patients with stroke, hemorrhage, or trauma. The typical incision is a reverse question mark (RQM); however, a retroauricular (RA) incision has been proposed as an alternative. The widespread adoption ofthe RA incision has been slowed by lack of familiarity and concerns over decompression efficacy. Our goal is to compare the RA vs RQM incisions regarding decompression safety and to examine skill acquisition among resident neurosurgeons.

Methods: Six cadaveric heads were randomized to first receive either RQM or RA decompressive hemicraniectomy, which was followed by use of the other incision on the contralateral side. Primary endpoints were decompression circumference and time to bone flap removal. Resident neurosurgeon (postgraduate year 3 through 7) confidence and operative times were compared.

Results: All craniectomies yielded decompression diameters >13 cm (RQM: 13.5-15.5 cm; RA: 13.0-16.5 cm) and residual temporal bone heights <1.5 cm (RQM: 0.5-1.3 cm; RA: 0.5-1.5 cm). There were no differences between the RA and RQM groups in decompression circumference (P = .6605), residual temporal bone height (P = .7121), or time from incision until bone flap removal (P = .8452). There was a nonsignificant trend toward a shorter incision length with RA (RQM: 37.7 ± 0.7 cm vs RA: 35.1 ± 0.9; P = .0729). Regardless of which incision was performed first, operative time significantly improved from the first craniectomy to the second (-174.6 seconds, P = .0186). Surgeon confidence improved more with the RA incision, and there was a linear association with experience and time to bone flap removal in the RQM (P = .04) but not the RA (P = .95) groups.

Conclusion: The RA incision may provide adequate operative exposure without significant changes in operative time. Cadaveric labs improve skill acquisition and should be considered during implementation of novel surgical approaches into practice.