Presenting Step-Ladder Expansive Cranioplasty as the Next Step After Decompressive Hemicraniectomy: It Is Different!

Abstract

Context: Decompressive hemicraniectomy (DC) is the final surgical remedy for refractory raised intracranial pressure (ICP). Even with years of experience and profound refination of technique, the procedure has less rewarding results in traumatic brain injury (TBI). Besides, arrangements for bone flap preservation and the necessity of follow-up surgery in the form of cranioplasty bring in unavoidable monetary and logistic burdens to the patients. Step-ladder expansive cranioplasty was conceptualized as an alternative to achieve adequate intracranial volume expansion to help normalize ICP, with immediate reinstitution of the Monro-Kellie doctrine. It is also expected to prevent cerebral cortical pressure injury to the cortex underlying the craniectomy defect. The evolution of this concept, as worked out on different models, the surgical technique, and our experience with this technique are discussed in this article. Evidence Acquisition: Multiple research projects undertaken by our team to build up the concept and acquire data necessary to plan the surgical procedure have been published over last eight years. This review article attempts to evaluate the existing knowledge and our clinical experience so far. Results: Step-ladder expansive cranioplasty allows an assured centrifugal displacement of the inner table and underlying dural bag at craniotomy site by at least 9 mm, thereby achieving a minimum volume expansion of 120 cc for a circular craniectomy defect of 10cm dia. Both of these parameters can be increased as considered necessary by the surgeon. Conclusions: Step-ladder expansive cranioplasty offers an alternative that takes the centripetal pressure exerted by the combination of the tensile strength of the scalp and atmospheric pressure off the brain surface while achieving an assured augmentation of intracranial volume that can be optimized on a case-to-case basis, based on our future understanding of the subject. While it can be a single-stage surgery for those satisfied with the cosmesis, a revision cranioplasty (if required) will be easier, cheaper, and cosmetically superior to the presently popular cranioplasty techniques achieving cover over a craniotomy defect routinely done after DC.