Retractorless brain surgery: technical considerations

Abstract

Background Retraction is necessary to access deep areas in the brain and skull base, but prolonged and forceful use of fixed retraction might be injurious. Several techniques were developed, in the concept of minimally invasive neurosurgery, to eliminate or minimize the use of fixed retractors. The authors discuss the technical considerations and limits in applying dynamic retraction in brain surgery for a variety of lesions using different approaches. Results We retrospectively collected 123 cases with brain lesions in diverse locations, were dynamic retraction, using the tools in the operator hands and was achieved successfully instead of fixed retraction. Cases with aneurysms were excluded, although retraction was applied during clipping only. Superficial and large masses that do not require fixed retraction as a routine were excluded also. We relied mainly on patient positioning to benefit from the gravity, proper design of the craniotomy, arachnoid dissection, cerebrospinal fluid aspiration, and internal decompression of the mass when possible. Different approaches for different lesions were utilized in our patients, subfrontal or pterional and their modifications in 45.5% of cases, suboccipital in 21.1%, retrosigmoid in 13%, the interhemispheric approach in 10.5%, transcortical to lateral ventricles in 7.3%, and posterior subtemporal in 2.4%. Dynamic retraction with the surgical tools was used successfully in all cases except 7 patients (5.6%) where we had to use fixed retraction transiently. Conclusion Several considerations are helpful and amenable to achieve successful brain surgery without fixed retraction. Utilizing the gravity, unlocking of the brain, choosing the surgical corridor, cerebrospinal fluid suctioning, and mastering of the microsurgical techniques are the keys.

Use of rigid, fixed brain retactors is harmful for the brain

“…Iatrogenic brain retraction injuries occur in around 10% of major procedures of cranial tumors and 5% of intracerebral aneurysms as previously reported (11)(12)(13)(14)(15). These injuries may range from mild edema to severe edema even contributing to mortality.…”

“…In some difficult surgical lesions there is a need of rigid retractors i.e. 5.7% in the study reported by Nazim et al (15). Rigid fixed retractors hide the normal anatomy, moreover in longer procedures like resection of brain tumors or clipping an aneurysm, prolonged application of rigid fixed brain retractors can cause contusion, ischemia or edema to the surrounding brain tissue that may result in irreversible brain damage.…”

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review

“…To provide some historical context to the surgical management of CSF leaks, the first instance of an intracranial repair of a CSF leak was in 1926, when a bifrontal craniotomy was performed and a fascia lata graft was sutured to repair the dural defect. This technique had a high risk of failure of up to 27% and required brain retraction, which had the possibility of causing injury to sensitive neurovascular structures [ 15 ]. To avoid brain retraction and its complications, a naso-orbital extracranial approach to repair leaks was pioneered in 1948 [ 16 ].…”

Predicting applied force on tissue with optical signals: development of a prototype brain retractor system using photoplethysmography

“…Some of the methods developed include dynamic retraction that involves surgeons periodically removing or reducing the retraction force applied to the tissue to allow blood perfusion. Positioning is a method that involves careful selection of the surgical route with tactful positioning of the patient to reduce or eliminate the need for retraction of healthy brain tissue 6,7 . Chemical methods of brain retraction use pharmaceuticals to reduce intercranial pressure and volume to give greater access 1 .…”

“…Adding to the difficulties, recent studies into retraction injuries are often missing key information such as retraction time or pressure 9 . Positioning may be useful in certain situations, but there are still cases where positioning cannot eliminate the need for retraction 7,10 . Additionally, positioning can cause other injuries to the patient due to the required position and duration 2 .…”