Brain retraction injury: systematic literature review

Cerebral retraction is frequently required in cranial surgery to access deep areas. Brain retractors have been systematically used in the past, but they have been associated with brain injury. Nonetheless, they are still used and, even recently, new systems have been advocated. The aim of this study is to provide a systematic and critical review of brain retraction injury. A systematic literature review was performed in February 2023 according to PRISMA statement. Search terms included brain retraction and injury, with their variations and pertinent associations. Studies reporting qualitative and quantitative data on brain retraction injury were included. Out of 1689 initially retrieved articles, 90 and 26 were included in the systematic review for qualitative and quantitative data, respectively. The definition of brain retraction injury varies and its reported incidence in clinical studies is 5-10%, up to 47% if cerebral edema is considered. Some studies have hypothesized threshold values of pressures to be respected in order to prevent complications, with most data deriving from animal studies. At present, there are no instruments for brain retraction that can guarantee full safety. Some form of cerebral retraction might always be necessary for specific scenarios. Further studies are needed to collect quantitative and, ideally, clinical and comparative data on pressure thresholds to develop retraction systems that can reduce injury to a minimum.

Using artificial intelligence to quantify dynamic retraction of brain tissue and the manipulation of instruments in neurosurgery

PURPOSE

There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our goal is to develop metrics quantifying dynamic retraction and manipulation by instruments during neurosurgery.

METHODS

We trained a convolutional neural network (CNN) to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon's dynamic retraction of brain tissue and, using an object tracking process, evaluate the surgeon's manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. A channel and spatial reliability tracker framework is used in conjunction with our CNN to track desired surgical instruments.

RESULTS

Our network achieved a state-of-the-art intersection over union ([Formula: see text]) for biological tissue segmentation. Multivariate statistical analysis was used to evaluate dynamic retraction, tissue handling, and instrument manipulation.

CONCLUSION

Our model enables to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. This model can potentially provide the surgeon with objective feedback about the movement of instruments and its effect on brain tissue.

Minimally Invasive Neurosurgery for Spontaneous Intracerebral Hemorrhage—10 Years of Working Progress at National Taiwan University Hospital

Intracerebral hemorrhage (ICH) is a life-threatening disease with a global health burden. Traditional craniotomy has neither improved functional outcomes nor reduced mortality. Minimally invasive neurosurgery (MIN) holds promise for reducing mortality and improving functional outcomes. To evaluate the feasibility of MIN for ICH, a retrospective analysis of patients with ICH undergoing endoscopic-assisted evacuation was performed. From 2012 to 2018, a total of 391 patients who underwent ICH evacuation and 76 patients who received early (<8 h) MIN were included. The rebleeding, mortality, and morbidity rates were 3.9, 7.9, and 3.9%, respectively, 1 month after surgery. At 6 months, the median [interquartile range (IQR)] Glasgow Coma Scale score was 12 (4.75) [preoperative: 10 (4)], the median (IQR) Extended Glasgow Outcome Scale score was 3 (1), and the median (IQR) Modified Rankin Scale score was 4 (1). The results suggested that early (<8 h) endoscope-assisted ICH evacuation is safe and effective for selected patients with ICH. The rebleeding, morbidity, and mortality rates of MIN in this study are lower than those of traditional craniotomy reported in previous studies. However, the management of intraoperative bleeding and hard clots is critical for performing endoscopic evacuation. With this retrospective analysis of MIN cases, we hope to promote the specialization of ICH surgery in the field of MIN.

[Brain retraction injury]

This review is devoted to various techniques for reduction of brain damage during retraction. Searching for reports was carried out in Russian and English languages using the PubMed database (n=721) without restrictions on language, date and study design according to the following keywords: «brain retraction injury», «spatula brain retractors», «tubular brain retractors», «retractorless neurosurgery». Primary screening and exclusion of duplicate manuscripts allowed us to single out the main group of articles (n=121). Some reports were excluded due to non-compliance with inclusion criteria (no description of methods, few references and insufficient data). The final list included 32 studies which were represented by cohort studies, retrospective analyses of surgical interventions, as well as experimental and laboratory studies. Small number of publications did not allow us to obtain unambiguous conclusions. Further research is required to reduce brain retraction trauma.

Tumor retractor: a simple and novel instrument for brain tumor surgery

Background

It is important to secure a surgical space during brain tumor surgery. One of the commonly used methods is to retract the brain. We hypothesized that the tumor can be retracted and that the normal brain tissue retraction can be minimized during surgery, and thus, the degree of collateral damage caused by brain retraction would be reduced.

Methods

The tumor retractor had a 90°, hard, and sharp tip for fixation of the tumor. The distal part of the retractor has a malleable and thin blade structure. By adjusting the angle of the distal malleable part of the tumor retractor, the operator can make the retracting angle additionally. Retractors with thin blade can be used in a conventional self-retraction system. To pull and hold the tumor constantly, the tumor retractor is held by a self-retraction system. The surgical technique using a tumor retractor is as follows: The first step is to fix the retractor to the tumor. The second step is to pull the retractor in the operator’s desired direction by applying force. After the tumor is pulled by adjusting the degree of force and angle, the surgical arm should be held in place to maintain the tumor retracted state.

Results

The tumor retractor was used to minimize the brain retraction, pulling the tumor in the opposite direction from the surrounding brain tissue. In clinical cases, we can apply the tumor retractor with good surgical outcomes.

Conclusions

A tumor retractor can be used to pull a tumor and minimize the brain retraction.

Postoperative Epileptic Seizures in Children: Is the Brain Incision a Risk Factor?

BACKGROUND

Postoperative seizures (PSs) after neurosurgical operations are common but little is known about the role of surgical brain incision on their genesis. This topic has not been addressed so far.

OBJECTIVE

To verify if the corticotomy affects the risk of PSs and postoperative epilepsy (PE) in children.

METHODS

One hundred forty-three consecutive pediatric cases operated on for supratentorial lesions at the same institution in the last 15 yr have been retrospectively reviewed by dividing them into group A, 68 children who required brain corticotomy mainly for hemispheric tumors, and group B, 75 children treated through extracortical approaches mainly for suprasellar and optic tumors. Patients with possible "epileptic" biases, like preoperative seizures, were excluded.

RESULTS

No significant differences have been found between group A and B as far as incidence of PSs (11.7% vs 14.5%) and PE (4.5% vs 6.5%), timing, and type of seizures are concerned after a mean 6.8 yr follow-up. The size of corticotomy in group A (<3 cm2 vs >3 cm2) had no impact on epileptogenesis as well as the other variables considered in both groups (age, sex, extent of lesion resection).

CONCLUSION

This study shows that the surgical cortical "trauma" would not represent a risk factor for PSs and PE. According to the present analysis and the literature, other causes seem to be involved (namely, electrolytic imbalance and brain gliosis). This information is important for preoperative surgical planning and postoperative management. A validation by both adult series and prospective studies is needed.